I am also guessing, but I think what she may mean is a frame that IS a mirror, with a clear hole in the center in which to place a photo. I have seen these in the past that are tabletop frames with easelbacks. As I remember, one back was held to the front with little metal clips (similar to uniframe or swiss clips), the other had holes drilled in all four corners with small decorative bolts that went all the way through both layers and fastened in the back with a tiny nut. The later was an antique brught in for repair...the easel back was missing it's tongue, and also one of the four bolts (and wasn't it fun trying to find one of those!!!).
If it has to hang on the wall, I think the idea of the small silver metal frame is spendid.
Leslie