“Floating” picture frame - fix (SG4 hitchin)

NEEDS FIXING: This is a picture frame that has two pieces of glass for sandwiching a picture between the two so it looks like the picture is “floating” in the middle. The black bit used to be stuck to the front glass but it has come off, so the glass and picture keep falling out of the frame when the frame is propped up. Fixable I think if you want to have a go!