Is it technology or is it magic?

This little gadget has blown my mind. Click the boxes to have your own mind blown.

The more boxes you click, the better it gets. (You can also click and drag to select multiple boxes at once.)

p.s. Make sure your volume is on! (And, no, it's not one of those it-mesmerizes-you-and-then-a-creepy-face-pops-out things.)