Review Mirror

I've spent a few hours in the dentist chair the last few days. Watching the dentist work by looking into a mirror got me thinking about how different his world must look. Sure I can drive looking in a review mirror, but I can not write my name looking in the mirror. I was always fascinated in how McLuhan kept pushing the review mirror concept and now I have a little more experience to add to the "rose is not a rose" about review mirrors.