I hate these sorts of pics. It is easy to trick the eye by circling a random bush and saying THAT is the sniper. Only ONE pic had the sniper stand up to prove it.
We did a perception exercise in a Psych course years ago that directly related to this. Prof came in and showed up five huge photos. Then passed out smaller copies of same. Asked up to study the big ones. In each one there was a man hiding. Wanted us to mark on handout where we thought the man was.
Turned out, there was a man hiding in only one. We all believed there was a man in each since prof said so, and manufactured in our minds where the non existent men were based on looking for a pattern or such that said "man hiding".
Myself and four others though we really sucked at it. We could not find anyone in two of the pics. I had a guy sitting beside me show me "where the guy was" in the ones I could not find. When he pointed it out, I believed him. There was no man hiding in those pics.
THAT is why I hate these sort of pics. I don't trust the red circles.