Thomas Nast print on glass what is it?

Hi, not sure this is really art in a true sense, but I am hoping someone can help me learn what it is and what it is called. It is the image of a Thomas Nast Christmas print that appears to be inside glass when tilted in light. Nothing seems to be raised on either side of the glass. I cannot find anything similar with any images other some stained glass type pieces with similar pewter frames. I would be grateful for any help or leads on what this is.

 

how is that glass in one piece with the severe damage to the frame !

 

@Kevolee -

I think that frame
Is just lead came,
And a soldering gun
Was used by some dame!

Best guess: it's a decal or transfer between two sheets of single-pane window glass.
.

 

Does this mean it has to be at a certain angle to the light in order for the image to be visible?

I don't see any way to hang it, but the Tiffany window type ones I have came with a little easel as well as with a chain & S hooks that attach to holes in the frame. Mine came from a museum gift shop. Yours may have had a similar source.

 

@Bronwen - Yours are doubtless copper foil method; this is simply lead came, and the lead is dead soft - it will stretch - sometimes sufficiently to let Mister Nast fall out into the fireplace, burning his Weihnachtsmann.
.

 

I don't know. They look like lead & are quite heavy. When one fell, frame bent a little & glass cracked without falling out. I was able to bend it back some. They are not truly stained glass. More like painted in enamels.

 

The image is visible at any angle and when held toward light it looks to be im ? em bedded inside of the glass. The cross hatching is very clear and detiled.