[drcy]

I don't know that T206s are stone lithographs, but that's really just a mnor technicality because its merely a matter of what the printing plate was made out of (limestone versus metal). Doesn't change the printing process or theories. As noted transfer lithography, which involves an intermediary step, allowed an image to be backward or foreword. I suspect they originally introduced it so the original art could be made normal instead of backwards. The artists didn't have to draw in reverse left to right.

The exact cause of specific ghosts are a mystery to me, and different ghosts may be the result of different situations. But, between wet transfers and transfer printing, it's definitely possible to get the reversed images.

Have to admit the first time I saw a ghost my first reaction was it was fake because the image was reversed, but I have no reason to disbelieve it now.