Why does Gretel make fun of Bruno?

Gretel makes fun of Bruno primarily because she sees him as childish and naive, especially in contrast to her own developing maturity. She often teases him about his lack of understanding regarding their family's situation and the realities of their new life near the concentration camp. This dynamic also reflects typical sibling rivalry, where she seeks to assert her superiority and cope with her own frustrations. Ultimately, her mockery highlights the tension and confusion both children experience in their unfamiliar and troubling environment.