I can understand adding the nipples to those lifeless bodies that showcase the fashion of the day behind large plate-glass windows. Nipples are cute, perky, and add some sexiness to the inanimate form. It makes the passer-by perhaps stop in front of the window and say, "hey! look at those boobies! Oh, and what a cute sweater, maybe I shall buy it and my boobies will look so pert!" I am sure that happens all the time. Plus, no one wants to have a mono-boob and the addition of the nips does indeed prevent this embarrassment.