Mainstream science, however, believes these items are not man-made at all. It argues the distinctive features have very probably been moulded by geological processes.
This is my opinion also. As an avid artifact and rock hunter sometimes rocks will naturally resemble something. Heck i even saw my ex-bosses face in the wood paneling once. But i used to party alot back then.
Basically the very first thing the human brain is wired to do visually is recognize a human face. It's deeply ingrained in our genes.
These don't look any more real than those Jesus or Elvis potato chips or whatever :-).