I get it all the time with Uni who is all of 5 pounds. I once had a brother and sister come into my store. The brother goes "Hey look a yorkie, it's a big one!" Then the sis goes "Oh yeah, mine's waaaaay smaller than that!" I asked how much does she weigh, and she goes "Oh like a pound or two pounds at the most". I stopped talking after that point bc I knew these two were absolutely idiotic and there would be no way of educating them. Oh this was also when Uni was still a puppy.
Most people that talk down to you and your yorkie due to its size are usually very ignorant and misinformed people. They are most likely also "rich" people that paid over $2000 for a pet store pup. They feel the smaller the dog, the more it shows how much they paid, but in actuality we know what it really means.