haha nice

Easy to do lol

'Flat cube' was all the time on the ground, that 3d cube was standing on them so camera's perspective didn't seen that.

In 0:14 he's hands are gone from screen - thats the time when assistant gives him ball instead of disk.

In 0:16- 0:17 he is taking the cube. Notice that: you dont see whole cube in moment of picking it up. So he took 3D cube unhiding flat cube.

In 0:21 is the moment when hes putting back 3D cube and you shall notice that that cube is taken by someone to the edge of right screen.

Cheap trick.

well you're almost right. the flat cube couldn't have been underneath because as the camera turns and jostles you'd see the lines. But, when he picks up the cube, he comes in close and off screen somone puts the 2d image down as well as sticks the front line piece to the ground - the one he takes off. as he goes back to the ground holding the 3d piece, he simply throws it off screen.

That's old.

I got a trick...Pull my finger.......

wooooqw