I was praticing one of the tunes, and i had the Military channel on. I found myself looking at the TV while i was practicing the chord progression. I thought this was cool, so i started praticing this on purpose. Certain shapes are easier to finger without looking, Like D to A, G, Em. Others, like Dm, and some of the 7ths, are harder, only because i don't play them enough. Repitition works the best, and i do better when i'm not thinking about it or trying too hard.
A mirror would totally confuse me, everything is backwards in a mirror, it would likely be more of a distraction than the Military Channel!