In Boyne's The Boy in the Striped Pajamas, how is Bruno used as a symbol of innocence that contrasts with his reality?

Throughout the novel, Bruno maintains his childhood innocence despite the horrific environment around him. Bruno refers to the Auschwitz concentration camp as "Out-With" and does not understand that his father is in charge of the systematic annihilation of Jews. Bruno's naive perspective symbolically represents how innocence can withstand unimaginable horrors. Despite being a German boy, Bruno views Jewish servants and prisoners as equals without prejudice. He does not understand why Shmuel is forced to live on the other side of the fence and is unaware that his parents' relationship is suffering. One of the most significant moments throughout the novel is when Bruno and Shmuel search for Shmuel's father in the concentration camp. Bruno and Shmuel are forced to march with other prisoners as they are led to the gas chambers. Once they are inside the chamber, Bruno holds Shmuel's hand and says that he is his best friend. Despite Bruno's physical death, his innocence remains unharmed, and he is pure throughout the entire journey. Bruno's innocence symbolically represents how friendship, love, and purity can endure the most inhumane environments and experiences.