Bruno does not want to be at Out-With. When they move, he doesn't like the house, and he feels that there is nothing to do. He looks around his new room and glances out the window. When Bruno is surprised, his mouth forms the shape of an O.
"...this time when his eye opened wide and his mouth made the shape of an O, his hands stayed by his sides because something made him feel very cold and unsafe." (pg 20)
Outside he sees the camp and the prisoners. He doesn't know they are prisoners. This is actually a foreshadowing of what will happen to him later in the book. Bruno goes to the person who is the closest to his age, his sister, Gretel, and tells her how miserable he is. He says that
"I said I don't think the other children look very friendly" (pg 26)
When she wants to see these other children, she notices that Bruno was making her nervous.
"...there was something about the way he stood there that made her feel as if she wasn't sure she wanted to see these children at all" (pg 28)
She is just as surprised as Bruno, and she doesn't have any answers for this questions. When she returns to her room, Bruno, again, looks out the window and notices that they are all wearing the same clothes. His reaction to that is
"How extraordinary." (pg 38)
Since Gretel could not help him, Bruno goes to his father to find out who those people were who were all dressed the same. His father replies,
"Those people.....well, they're not people at all, Bruno." (pg 53)
Bruno is curious, but he is innocent, and that innocence is the backbone of the story. He soon meets Schmuel and forms his own opinion of those people.