wtf? what's going on here?

I think it's a fake. Note the mouse is off screen, someone probably hit the mouse button to change pictures.

Moving this video to ant's personal queue. It failed to receive enough votes to get sifted up to the front page within 2 days.

This is interesting. If it's a fake, they're not using the mouse. You can see the mouse in the reflection of the screen... the silver stripe can be seen... it's near the corner of the keyboard, and it winds up behind the "R" in the word "Wallpaper" on the screen when the flash is popped. There is no hand on the mouse. Also the message that pops up in the lower right makes it seem like the background is real and not just a couple JPGs being switched between.

On another board someone theorized that maybe the flash wreaked havoc with the LCD crystals themselves. Nope, it wouldn't knock out just the right half of the screen with a straight line down the middle.

Better theories:
Could a small EMP from the flash damage a chip behind the screen if it were right near the flash? Notice how close they put it to the screen. Maybe there is a separate driver of some sort for the right and left halves of the display. Maybe the light sensor that keeps the brightness comfortable in different lighting conditions produced a spike Asus never saw before in testing, and knocked out a chip. Possibly only temporarily.

It'd be interesting to know if anyone else has tried this, or if Asus has responded to it.