The area is ever so slightly smaller than the previous shape.

It's not a serious question, is it?

The fact that the "case" is placed out-of-camera-frame, combined with the cuts in the video give plenty of chances to cheat.

it's not camera trick or a switched out case, it's an old geometry trick.

When he counts the tiles, he's counting but he's als like "fuck you, you'll never know how I do this."

Amazing.

That was lame... He switches the tiles when he cuts the video. Count the tiles at 0:55 and you'll notice he has half a row more than before the cut. Same thing at 2:35 but now he has half a row less. After the shuffling he ends up with 9 rows that fit perfectly in the frame.

@Stormsinger: I've seen this done in real life and there's no such trickery needed. This puzzle was presented in another sift (which I can't find) a few years ago along with a link to a downloadable PDF that you could print and cut out the shapes.

edit: It works similarly to this: http://en.wikipedia.org/wiki/Missing_square_puzzle

edit2: The other video I was talking about is http://videosift.com/video/Illusion-The-Impossible-Puzzle

You've clearly got the right explanation, but now I wonder just why he had the video cut in those two places. All it did was add yet another opportunity to cheat (which is all that the near-triangle gimmick is, really).

Ya, it's a geometrical *illusion.

Adding video to channels (Magic) - requested by Norsuelefantti.

It could be as simple as he knocked the thing over, or sneezed, or a cat jumped up onto the table. But yeah, cuts are going to arouse suspicion in a video like this. He should have reshot the whole thing instead.

http://i.imgur.com/7zdpCjF.gif

Yah, do it with zero cuts, an a lot less of 'magic hands', where you kinda make unnatural looking clenched palms, and less of moving your hands in unnatural ways that looks like you are hiding something. It all makes it look fishy instead of amazing. Of course, if you are trying to make a geometry trick instead look like *you* did something, then maybe adding magic flourishes is the thing, I suppose.

It would have been a better illusion if he only took out 1 square instead of ambitiously taking out 3. Even in the crappy youtube encode, you can see that the grid doesn't match up well at all in the center. It would have been harder to detect otherwise.

We did this puzzle in elementary school in the GATE program. How on earth people aren't taught, amazed, and remembering this simple but awesome geometrical illusion is beyond me. First thing you see when you try to recreate it on a grid, is that there is missing diagonal space. People miss the missing space isn't using the same modular shape as the rest of the puzzle. Easy to detect on a grid using only a triangle.

I suspect it isn't widely taught because there's simply no practical use for such a gimmick. Those that were taught about it probably heard about it just because it tickled some teacher's funny bone.