Our initial count of these miniature men is 12, but just as soon as they slide around, a 13th man pops up.
Albert Einstein or Marilyn Monroe Illusion
When you look at this picture close range do you see Albert Einstein.
Now take several steps back, roughly 15 feet away,
It will become... Marilyn Monroe.
This image appears to bulge, although it only consists of squares.
Use a ruler to see if the lines are straight?
Do you see a perfectly round circle below viewed up close?
Move away 20 feet and the circle becomes a circle