I’ll admit it. I tried this out the first time I was in the bathroom after seeing the video.
I did NOT however, take any pictures using a phone, with the camera visible in the frame, or a toilet in the background.
Now, since we all know that the closer you get the bigger things appear, with a short focal length, this trick could really end up giving the Lisa Simpson, i.e. small body-big head, effect. So, if I ever get a portrait gig, I’ll be sure to stick w/ the 85mm (136mm eq.). I suppose if all you’re after is the head shot, while most of the body is not visible, then it doesn’t really matter how huge someone’s noggin looks.