How does Bruno identify with Shmuel's story about his house? What is the difference between their two situations?

Bruno identifies with the fact that Shmuel had to unwillingly leave his home without choice, as he had moved to Auschwitz in the same manner, unhappily and unwillingly. The difference between them was that Shmuel was forced from his home, his family losing all they had to be imprisoned in a concentration camp. Bruno had merely moved because his father was promoted.