How does talking about shmuel to gretel help Bruno understand his friends?

Talking about Shmuel to Gretel helps Bruno articulate his thoughts and feelings about his friendship with Shmuel, which deepens his understanding of their bond. It contrasts his innocent view of friendship with Gretel's more naive perspective, highlighting the differences between their experiences. This conversation also emphasizes the societal divide and prejudices surrounding them, prompting Bruno to reflect on the injustices faced by Shmuel and others like him. Ultimately, it reinforces Bruno's sense of empathy and the importance of true friendship.