It's hard not to have your photo taken by these machines.
Sometimes I'll purposely move my hand or body in front of the lens to make sure that the camera is working.
Other times, I'll mistakenly walk in front of the whole set-up.
One thing to take note of though, is that there has yet to be a decent picture of me from these cameras. Either I'm panting with my tongue out or a body part is chopped off completely.
The purpose of these cameras is not for glamour shots, though I do find some kind of weird satisfaction in writing "Homo sapiens sapiens" in my log books.