That is cool!
I use to be a picture framer once upon a time, and we used a non-glare type glass or plex-glass in some of the frames. This looks very similar, but it looks like a texture has been added to the non-glare glass to emulate the texture of an oil painting.
I don't know if this would work, cause it just popped into my head, but you might try painting a layer of Modge Podge on a pane of glass, leaving the brush strokes in it to create a similar effect. I may have to test that on a small scale to see if it works.