Weird...

[A Black Falcon]

[OB1]

[Sacred Jellybean]

Aren't you s'posed to tell us to count how many people are in the picture, then recount after the picture changes? I certainly wouldn't have figured that out on my own, had I not seen this before and had it explained to me.

Anyways, this was an activity we did virtually every year in elementary/middle school (only WE HAD TO FIGURE OUT THE BORDERS OF WHERE THE PICTURE SHIFTED AND HOW USING A HARD COPY OF THE IMAGE; it was always hard, depressing school day that reminded each of us how sadistic and merciless the teachers genuinely were), so I recognized this right away.

[A Black Falcon]

Oh, right, yeah, you're supposed to watch it and try to figure out how the number of people changes from 13 to 12... I watched it for a while but couldn't get it...

[Laser Link]

That is awesome. If I didn't have so much to do right now, I would study that until I figured out how it happens.

[A Black Falcon]

I got it from here. There are some confusing explanations on how it works...

http://www.yakyak.org/viewtopic.php?t=12185

[Fittisize]

Hmm...one pair of shoes doesn't move at all...it's like, the fifth guy from the left when there's twelve people. And he's in the middle, and that guys shoes joins another guys shoes.

Man this is hard.:S