Small part dropped out during repair, where does it go?

Hi, I recently tried to install a new screen in my iphone and during re-assembly a small silver clip about 4mm long dropped out, I have looked at all the 4 exploded views I can find, and that part is never there.

Also cant get the face sensor to work at all. It didn't before i put this new screen on, i was hoping this screen would fix that. Tried all the basic tricks (no screen protector, network reboot, the tape & sharpy trick) but it still does not work!

Any and all help welcome!

Thanks. st3fan