The original question had to be edited. I would suggest that most of what Bruno does can be seen as representing innocence. Bruno operates in such an innocent fashion that he is unaware of his innocence. It is simply how he is. The quotes that show this are ones involving third person narration to illuminate this quality:
“What exactly was the difference? he wondered to himself. And who decided which people wore the striped pajamas and which people wore the uniforms?”
This quote is one example of how narration brings out Bruno's innocence. After being given the order to not concern himself with what lies outside the fence in "Out- With," Bruno wonders openly about who the people in the camp are and what they were like. The idea of "wonder" is reflective of innocence, for it is done openly and without much in way of ulterior motive. At the same time, Bruno is able to display the innocence of a child in that he sincerely wants to understand and explore what is out there in "Out- With."
Another example of innocence would have to be at the end. It is at the end when Bruno displays the heroic type of innocence that makes him transcendent in his goodness, universal in what he represents:
“...Despite the mayhem that followed, Bruno found that he was still holding Shmuel's hand in his own and nothing in the world would have persuaded him to let go.”
The scene around Bruno is one where innocence is easily discarded. Yet, "he was still holding Shmuel's hand" and "nothing in the world would have persuaded him to let go." The authenticity and innocent beauty of this instant is what transforms Bruno into a paragon of goodness and honor that the reader can only hope to represent in their own sense of being. Bruno's innocence is evident in this quote in how he clings to his friend, offering his support to him in the most intense time of crisis. When Bruno precedes this with reassuring Shmuel that he is "his best friend for life," it is reminder of how innocent Bruno is. While the world around him literally burns, Bruno is more concerned with affirming and representing friendship.