Mitch - its for showing, the ears need to be folded over and taping/gluing is one way of allowing the ears to develop and grow in such a manner that the tendons and muscles allow the ear to fall how it is supposed to. If the ear is a smidge small then it has a tendancy to lift and make your schnauzer look like a fruit bat - not ideal for the showring. It doesn't hurt the dog and has no affect on them - just makes them look like schnauzers. I suppose you could think of it as slightly extreme grooming.
Cara and Mo, two black mini's served by Elaine, the cook, poop picker, and chief toy thrower.
I live by the Mini Schnauzer code; when in danger or in doubt, run in circles, scream and shout!