How does Elie Wiesel use imagery in Dawn?

Imagery:

"I'm going to teach you the art of distinguishing between day and night. Always look at a window, and failing that look into the eyes of a man. If you see a face, any face, then you can be sure that night has succeeded day. For, believe me, night has a face." Chapter 1, pg. 4

"Death is a being without arms or legs or mouth or head; it is all eyes. If you ever meet a creature with eyes everywhere, you can be sure that it is death." Chapter 2, p. 22