Answer:
Bruno, being the son of the Commandant of the Nazi army who is in control of the concentration camp that housed the Jewish prisoners, he is a healthy boy. On the other hand, Shmuel was sickly and thin, being a prisoner of the camp.
Explanation:
Bruno and Shmuel are the main protagonists of "The Boy in the Stripped Pajamas" by Irish novelist John Boyne. This holocaust novel revolves around the unlikely friendship between the son of a Nazi officer and a Jewish prisoner of the concentration camp overlooked by the boy's father.
When Shmuel was taken int the house of the Commandant to help in the kitchen work. It was there that Bruno saw Shmuel for the first time outside of the fence. He had been taken "to polish the glasses [.... for] they needed someone with tiny fingers". And once Shmuel held out his hand to show how "tiny" his fingers are, Bruno noticed how different their hands looked. His "appeared healthy and full of life" while "Shmuel's hand, however, told a very different story".
Bruno obviously is more healthy unlike Shmuel as he was the son of the Commandant and was free to eat whatever he wished for. While Shmuel was a prisoner who have all been deprived of many things, like for instance enough food to eat. Shmuel proclaims that "Everyone on my side of the fence looks like this now", which shows the drastic effect the camps have on them.
