Portrait of Hitler on glass and signed

[D. Ricks]

I don't know if this is the right forum for this but here goes. Just bought a bunch of WW1 and WW2 items and this was in the group of items. It measures 4 1/2" x 6" and in a soldered metal frame. It looks dull unless you hold it to the light. It's signed in the corner but I cant read the name. You get a left view or right view of the portrait by just flipping it as shown. Does anyone know what this is called and can you tell me who the signature is? Thank you

[D. Ricks]

pics #2

[D. Ricks]

pics #3

[J. Wraith]

I think you have located the missing link between stained glass and the glow in the dark black velvet Elvis poster.