Click on "Read more…" to read the solution!
The bottom (static) tile has 12 dudes (counting the sliver of feet for a couple of them.)
The two top tiles also have 12 guys, counting tips of hair and so forth.
In one configuration, the 12 top guys match the 12 bottom dudes and their are 12 guys total.
In the other configuration, one of the bottom guys is missing a bit of hair and one of the top guys is missing a bit of feet and their appear to be 13 guys.