It's a grip safety, like the beavertail on a 1911. Normally it refers to a few old S&W and H&R revolvers, and just called a lemon squeezer. Never seen/heard of one on a glock. Maybe its a super rare H&R Glock hybrid in .32.
Printable View
Here found an example. I'd hazard a guess that shes seen one of these before and didn't know what else to call those funny looking triggers they put on glocks ;)
http://i807.photobucket.com/albums/y...h/100_2812.jpg
It's possible to put a beaver tail setup on a Glock. I forget which company does it, but it's an aftermarket option!