"Your reflection is always half the size of the real thing – no matter how far from mirror. Hard to believe but true." This is simple physics. well not simple, but physics anyway.
Lawson et al (2007) http://scienceblogs.com/cognitivedaily/2009/03/mirror_images_you_dont_perceiv.php – also decribe how people misjudge the size of objects on mirrors – specifically, they think the projection is larger than it actually is…this is simple psychology, well not simple…oh you get it!
Hmmm…physics versus psychology! Who wins?