What is this type of fastening called and what does it fasten to?

This belonged to my grandmother (the clasp looks post 1930). I assume there would have been some kind of hinged cover over the watch face  (a hinge and catch  are circled). I don't know what the double fanged clip like  thing on the back is called or what it is for.  The double 'fangs' look somewhat like an upholstery pin.  Given that the front is a watch, and one needs to see a watch for it to be useful.... what would this be stuck into or clipped onto?   Anyone familiar with this style? 

Picture of What is this type of fastening called and what does it fasten to?
P9120002 copysm.jpg
P9120003 copysm.jpg
hinge.jpg

It's a broach that has a couple different ways to wear it on a jacket, shirt, belt, or a hat. It has a vary versatile set up there for wearing it. The cover was likely fairly ornate. So it wouldn't have mattered if you could see the watch or not.

mole1 (author)  mpilchfamily2 years ago

I think you're right, mpilchfamily. The clip would be useful for a
belt or scarf, or whatever. One wouldn't have to pull the whole thing
through the back, just clip it on where needed and pin to secure. I was getting hung up on the fangs... wondering what to stab with it.

definitely a broach