These images are what happens when you combine a a random polygon generator with a "facial recognition algorithm".
Which means the generator keeps generating until the recognition algorithm detects a face. Then it keeps running while it tries to automatically improve it. To...mixed results.
In short: it's a million virtual chimps drawing a million virtual polygons until one of them somehow churns out a face, with no prompting or intervention from a human being whatsoever.
It's equal parts soothing and terrifying to see.
The program, called pareidolia, is named for the phenomenon Pareidolia, which is "a psychological phenomenon involving a vague and random stimulus (often an image or sound) being perceived as significant".