Astronomer Carl Sagan argued that perhaps recognizing faces, even in vague shapes, is evolutionarily advantageous.

Joel Voss proposes another explanation: Think of the human brain as a flexible, all-purpose machine meant to succeed in whatever random environment it inhabits. To triumph in strange places, the brain must be able to quickly process unfamiliar visual stimuli—like new shapes and lines—and figure out what's worth paying attention to. Seeing faces and figures is merely a consequence of the brain's tendency to match stored information with new stimuli.

• Although we see the world as this very structured, object-containing environment, it's really just a bunch of random lines and shapes and colors,
• The reason why it's so easy to see meaningful things in nonsense shapes is that those nonsense shapes have a lot of the same features as meaningful things.
• In scientific terms, what a moon-gazer sees may come down to brain wiring. But through the ages, what civilizations perceived in the moon's face took on greater significance, in the preservation of cultures, origin stories, and beliefs.
• The night sky is one of the greatest storytelling panoramas. Things in the natural world are the hints and clues for the story. When you see the moon, you remember the story you heard when you were a kid and you pass it on.