What is one example of Dramatic Irony from chapter 10

Bruno sees the boy is wearing the striped pajamas that all people on the other side of the fence wear, and on his upper arm is a band with the Star of David on it. Bruno doesn't know what the star is, but he notes the symbol. Bruno is "sure that he had never seen a skinnier or sadder boy in his life". Bruno has know idea what is going on but the reader knows that the boy is a prisoner, most probably Jewish, in the concentration camp Auschwitz.