Foto Fold's - Any Ideas?

As I was going back over some items I have in my Aunt’s photo collection (she died in 2000), I found two unique items that I can’t seem to find out anything about.

They are called “Foto Fold's" and are raised pictures in a fold-able container. I’ve attached three photos:

Closed image shows the two closed. One is the back and the other the front which is die cut.

 

Opened image shows both opened. One is a single picture of my grandmother and the other my Aunt, father and grandmother (their mother).
 

Side View shows that the item is not flat but raised. The raised part fits into the cut out piece on the right which then closes to the fold-able container.

I don’t know when these were taken but my grandmother died in 1956 so it is before that. My dad was in the army until 1945 so it is after that. He was born in 1910 so I’m guessing that it is either late 1940s or early 1950s. 

Any information that you may have regarding this type of photography would be appreciated.