Funny enough but I *think* that his question can be solved..
It's a very cool effect, I also tried something similar a few years ago when I had way to much free time to attempt a sort of image that would turn the background into a sort of window.
(not mirror thought)

Sorry about the desktop image on the laptop - I wasn't a married man at the time..
He can take several pictures until he gets it right, although the idea of scanning a mirror is a bit pointless, isn't it?
--
Funny enough that this weekend I went outside to a coffee on the beach with my wife, I was feeling a bit bored of the books and took some pictures of her while we were studying. Removed the SD card and copied all the photos onto the computer. I liked a lot of one particular image where she was looking on the books while doing her homework and I placed this image as the desktop background for that day.
Strange enough when the coffee owner came around to ask us what we'd like to drink and he became petrified to see the computer screen display an exact portrait of her sitting at my side. He was left static for some 10 seconds looking at this "mirror" effect until I explained him that it was no magic and had been done with a simple digital camera..