True Mirror - wow

It just occurred to me that mirrors aren't what you look like to others. They reverse the face or whatever they're reflecting sideways - left to right but not top to bottom. I'm a little dense I guess and that made me think but I thought into a wall. Duh. So when I used the webcam on my laptop to take a photo which barely showed the scales that caught the cockroach the other day, I put my hand up on the right side and there it was on the left in the image I was looking at. It was a true mirror. I knew I couldn't be the first to think of that and found True Mirror dot com and a Guardian article on why mirrors go L to R but not top to bottom.