Explain the significance of the final image in Night?

In the conclusion of the novel, we are left with the image that Elie saw in the mirror. Elie hadn't seen his reflection since he was taken to the ghetto, and the young boy he remembered had been replaced by an old man..... a corpse. The image that Elie saw looked back at him for the rest of his life..... he'd lost his family, his friends, and his humanity. The face he saw in the mirror reflected that loss.