My littlest, Ellie, does.
We have two mirrors low down on either side of the fireplace. Every time she notices herself she sets off growling at this other strange dog. Her toy box is often in front of one of the mirrors & she goes bananas when she sees this dog trying to get at her toys from the other side of he box at the same time as her!
My two older Yorkies don't bother, but one of my Ske Terrier puppies is just as bad. She'll really growl at it, but what really gets her is how this other Skye manages to reach the other mirror at the same time no matter how fast she runs!
