Wow. I had no idea people did that.
Of course, I had no idea people could even see pictures in their head until I was 20 or so. My brain is all about sounds and physical positions. I remember phone numbers by saying them in my head repeatedly until the sequence of sounds is familiar, or sometimes by dialing the number three or four times until "my hand remembers".
Of course, most people expect other people to have visual recall (at a minimum) and visual imagination (hopefully). Since I have neither, I'm sometimes confused by instructions from others that are visually based, and by icons, especially when the interface is solely icon based. Ick.