Outside their window in The Boy in the Striped Pajamas, Bruno and Gretel see a desolate looking area that contrasts sharply with the lush garden directly beneath Bruno's window that was "full of flowers" and had a "very pleasant pavement with a wooden bench on it, where Gretel could imagine sitting in the sunshine and reading a book."

In the barren area beyond their garden, they see people who appear to be working hard and who also appear to be very different from any other group of people they have ever seen, although they cannot quite understand what makes this group of people so different. They are puzzled by what they see, and Gretel asks Bruno,

"What sort of place is this?"

"I'm not sure," said Bruno, sticking as close to the truth as possible. "But it's not as nice as home, I do know that much."

Beyond the landscaping of their home, "there was a huge wire fence" that was topped by "enormous bales of barbed wire." They see low huts and ugly large square buildings and "one or two smoke stacks in the distance." They do not understand that those are buildings intended for mass killings.

Bruno disagrees with his sister's theory that they are looking at a countryside environment. While neither child can really articulate it, each feels a sense of dread and fear about the area outside their home. People are fenced in, commanded by soldiers and made to wear the same tattered rags that resemble striped pajamas.

"Who are all those people?" she asked in a quiet voice, almost as if she wasn't asking Bruno but looking for an answer from someone else.

"And what are they all doing there?"

They are puzzled by how desolate the area appears and that there are no women or girls beyond the fence, only men and boys. They are puzzled that some of the men have bandages or crutches. Most of all, they are puzzled by how packed in all the people appear to be in small huts with no distance between them and how filthy looking the people appear, even the children.

When Bruno and Gretel look out of the window of their new home, at first they see a very pleasant sight. Beneath the window is a very large garden full of pretty flowers growing in neat orderly sections. It looks as if someone has really made the effort in planting them.

Past the flowers, there's something else that's pleasant: a nice little pavement with a wooden bench on it, a place where Gretel can imagine reading a book in the sunshine.

But that's where the pleasantness ends. Further along from the garden, the pretty flowers, and the nice little bench is a huge wire fence that runs along the full length of the house, extending further along in every direction, as far as the eye can see. The children don't know it yet, but this is the security fence that keeps the inmates of Auschwitz from escaping.

All along the top of the fence, one can see coils of barbed wire. Gretel feels pain inside her as she contemplates the sharp spikes sticking out all the way around it.

Beyond the fence, one can see low huts and square buildings dotted all around the place and two smokestacks in the distance. The children are blissfully unaware that these are the giant crematoria used to dispose of the bodies of Auschwitz prisoners murdered by the Nazis.

Although Bruno and Gretel are still too young to understand what Auschwitz is all about, they do at least know that it's a nasty-looking place.

In chapter 4 of the novel, Gretel follows Bruno into his room and stares out his window to see the Auschwitz concentration camp for the first time, which is located next to their new home on the opposite side of a high barbed wire fence. As Gretel and Bruno look out the window, they are confused by the people inside the fence and struggle to identify the concentration camp. Both children are too young and naive to recognize that they are looking at one of the largest Nazi concentration camps and that the men and boys wandering around are actually Jewish inmates. Gretel immediately questions where the women are located and cannot discern the function or exact nature of the mysterious environment.

All the children can see are low huts and a few large square buildings with smokestacks in the distance. Both children agree that Auschwitz is a "nasty-looking place," and Gretel mentions that the huts must be modern types of houses. Initially, Gretel concludes that they are looking at the "countryside," which explains the lack of shops, schools, and different homes. However, Bruno comments that there are no farm animals or good soil to grow crops. They also notice groups of prisoners marching as soldiers give them orders and wonder what kind of people live in such a dirty, depressing environment. Bruno also cannot explain why everyone is wearing the same grey striped pajamas, which are actually prison uniforms. Overall, Gretel and Bruno see the Jewish prisoners following orders inside the Auschwitz concentration camp when they look out the window together.

This question can be answered by reading Chapter Four:  "What They Saw Through the Window."  The short answer to your question is that Bruno and Gretel see the Jewish prisoners at Auschwitz.  Because the concentration camp is right across from the Commandant's house, the Commandant's two children are not protected from seeing the prisoners walking about behind the fence.  Bruno and Gretel are confused.

There were small boys and big boys, fathers and grandfathers and perhaps a few uncles too.  And some of those people who live on their own on everybody's road but don't seem to have any relatives at all.  They were everyone.

They see "a nasty type of place" with what they think might be "modern types of houses" found on what they can only believe to be "the countryside."  This is where Bruno gets the mistaken idea that the people behind the fence are farmers; however, Bruno wonders why there are no farm animals to be seen.  Further, the two of them decide they can see hundreds of people, but that there must be thousands behind the fence.  

And one final thought came into her brother's head as he watched the hundreds of people, ... all of them--were wearing the same clothes as each other:  a pair of grey striped pajamas with a grey striped cap on their heads.

This quotation, of course, is where the title comes from.  These "grey striped pajamas" are striking as the hundreds of people walk around inside the Auschwitz fence.  These are the people that Gretel and Bruno see outside their window.

From The Boy in the Striped Pajamas, what are Bruno's thoughts and understanding about what he sees outside his window and what his father tells him?

In The Boy in The Striped Pajamas, Bruno is an inquisitive boy, not at all impressed with his parents' decision to move out of Berlin to "Out-With". He can see out of his window what to him looks "desolate" and which Gretel, his sister, first thinks may be the countryside but, after consideration, they both decide that it is definitely not the countryside. Bruno and Gretel can see the people in the camp on the other side of a fence and, although it makes no sense, Gretel imagines they may be actors, busy with a rehearsal. Bruno is particularly interested in the fact that there are children - definitely scope for some friends. Gretel, however, is not impressed with the appearance of these children and thinks they are definitely not her "type."

Bruno persists in his interest and manages to gather enough courage to approach his father. His father's response foreshadows what will follow but Bruno, the innocent and ever obedient son, does not question his father, or the meaning of his father's words, although his answer is not what Bruno was looking for :

They’re not people at all...at least not as we understand the term....You have nothing
whatsoever in common with them. 

From The Boy in the Striped Pajamas, what are Bruno's thoughts and understanding about what he sees outside his window and what his father tells him?

When Bruno moves with his family from Berlin to Out-With, he is not very happy.  He knows that outside the house, the surrounding area is okay to explore, being a town which his father has been transferred to, except for the forbidden area which he must not go to, no exceptions. He is basically told that this town is just another place for the family to live.  Being a young boy of eight, Bruno wants to know everything about the area around his home, and being the curious boy that he is, he goes exploring.  Of course he goes to the forbidden area where he finds a fence with another young boy on the other side.   He, in his innocence, has discovered Auschwitz.  Since it is forbidden to be there, he tells no one in his family that he has been to the fence in the woods.  The story ends in tragedy.

In The Boy in the Striped Pajamas, what is Bruno's worldview and how has it changed?

In The Boy in the Striped Pajamas, Bruno's inclusive and respectful worldview is strikingly consistent throughout the narrative.

Bruno's view of the world shows that people matter.  From his friends back in Berlin to Shmuel, the need for people is a very important component to his worldview.  Bruno validates people in profound ways, such as his friendship to Shmuel.  He also does this in small ways, such as when he validates Hitler's girlfriend as a nice lady.  Bruno's worldview is not politically intentional.  Rather, he simply treats people as he would want to be treated.  

Bruno's worldview emphasizes the need to atone for mistakes.  He understands that errors in judgment may happen.  Yet, figuring out how to make mistakes right is a significant part of what human beings should do.  He rectifies his mistakes such as with Pavel or Maria, and understands that he erred in letting Shmuel get abused from Kotler.  In these cases, Bruno is quick to make amends.  It is why Bruno is so loyal to Shmuel, even in the darkest and scariest of moments. Bruno's worldview towards people remains consistent throughout the novel.

Another aspect of Bruno's worldview is to represent what is right and decent. Bruno approaches the moral complexities within the Holocaust with a stark sense of ethical clarity.  He wants to be nice.  It is why he has such a disdain for Kotler.   Additionally, when "The Fury" comes to dinner, Bruno is not pleased with the way he orders Eva Braun and snaps his fingers at her.  Bruno's worldview affirms respect and he does not like it when others are disrespected.  It is why he sees the people at "Out-With" as simply the people "in the striped pajamas." Bruno's inability to call them prisoners or even "Jews" shows how he sees them as people.  Showing respect to people is a significant aspect of his worldview that is very consistent throughout the narrative.