What causes the shapes we call 'the man on the moon'?

The craters, mountains, and valleys of the moon appear as different colored areas on the surface. The low, flat "seas" are dark and the higher mountains are light in color. That's what causes "the shapes" . . . however, there is a psychological phenomenon called pareidolia that involves vague and random images (or sounds) that are perceived to be significant.

Other examples of pareidolia include seeing images of animals or faces in clouds, or hearing something in a recording played backward . . . or even seeing religious icons in the stump of a tree or on a grilled cheese sandwich!