Physical description unnecessary in real life

As a teacher, I abide by a simple and unusual rule in my classroom:

No compliments based upon physical appearance. 

I do not comment on a student's wardrobe, hairstyle, shoes or anything else related to the student's image, even if he or she asks. 

Student: Mr. Dicks!  What do you think of my new haircut?

Me: I think your memorization of the multiplication tables is outstanding!

Some think this policy a bit extreme, but having grown up wearing hand-me-down clothing and the cheapest...