I can do this, sometimes, for short periods (but if you look at Brenda and Rhonda, they don't always get all the way off the ground, either). The "Secret" is not to bend at the wrists, which makes it tough on them, and seemingly impossible for me to do), but to splay our fingers, and bend where the fingers join the hand. This is how I used to do push-ups for quite a while, when my carpal tunnel would sometimes bother me.
The problem I had with the levitation move, when I could get up, was that I tended to tip backwards! Guess I'll have to experiment with hand placement!