Technically, the top two people are 'planking' while the bottom person is 'facedown'.
CNN had this interesting video report on a new craze. I’ve seen a number of these posed pictures over facebook, and it makes me wonder what about the human existence and our culture craves this kind of randomness and silliness. Not that I have anything against it. I’m just wondering what gives? Any hypotheses?
Echoes of the Myth 
now that you mention it, i am curious too. in korea, this is known as “시체놀이” (playing dead). you don’t necessarily have your face downward, but you pretend you are dead, letting your limbs go listless.