How do shame and remorse figure into the friendship between Bruno and Shmuel? How does Bruno show his remorse?

This is actually a fairly involved question. It takes a little time for Bruno to figure out what is going on with Shmuel behind the fence. Bruno certainly feels uneasy. He knows that Shmuel is hungry and lives in filthy conditions while he (Bruno) lives in comfort. Bruno begins to sneak food to Shmuel out of both compassion and shame. Eventually Bruno joins his friend in the "showers". Did Bruno have any inkling of what might happen? We can only speculate that Bruno had moved beyond shame and compassion to a real empathy with his friend.