Hedy LaMarr Picture

Hedy Lamar picture-I found this in my mothers things after she passed away. She knew every actor and actress and the movie they stared in. remember seeing it my Grandmothers house when I was 10 yrs old. I believe my grandmother gave it to my mother. My grandmother was 87 when she passed 20 yrs ago.
The picture has a stamp on it that says "Hedy LaMarr" then under the stamp-looks like "in M.G.M. and then under that says"painted in U.S.A."
Is it sometype of advertisement? The paper is so fragile, I have to move it around on top of a piece of cardboard to get the picture. Any suggestions is appreciated.