This is a false conclusion. Dogs know the reflection in the mirror is not another dog because it has no scent. Everything alive has a scent.
-PJ
Dead has a pretty strong scent as well...............
My Ibizan Hound stands on the arm of the sofa and obnoxiously admires herself in the mirror on the wall adjacent.
She poses, wags her tail and then barks at me to see if I’m watching this vulgar display of vanity.
OTOH, Seven, the Dobe, saw her reflection the first time in a PetCo bathroom mirror.
She went ballistic over that “other dog” who was standing so perilously near me.
When I touched the mirror dog’s head and then hers, she stopped barking and “high fived” the dog in the mirror, instead.
This article is rubbish.