A while back I had someone inadvertently flip the screen on his desktop
(mirror horizontal image) while we were looking at Excel. Don't know if it
was an Excel function, or a windows function (this was not on a laptop, but
if it's an intentional function, my guess is it allows you to basically lay
your laptop screen flat, and have someone who is looking from the other side
see an image right side up).

Any idea what this might have been, and whether it's Excel specific? I'm
doubting it, but thought I'd post here. Thx.
--
Boris