He is using right hand to move the cup. So its easy to recognize.
He taught the Crazy bichon frise lady shirt to keep his eyes only on right hand. Why are people so negative, that dog is probably smarter than most people, who cannot take their eyes off their smartphone, at least the dog is paying attention! Using the right hand in each case makes it easier to track the right cup. But, yeah, her hand never left the cup and his eyes never left her hand. The dog just has to follow her right hand. She never takes her hand off the cup.

Crazy bichon frise lady shirt, hoodie, tank top and sweater

Crazy bichon frise lady Ladies

Ladies

Crazy bichon frise lady Hoodie

Hoodie

So beautiful I had one the Crazy bichon frise lady shirt about 15years ago that was the family baby, we had her for about over14years such a smart little one, yours is so beautiful and smart you must enjoy her as much as we love those little dogs! It would be more impressive if they sometimes moved two empty cups. The dog is following the hand, not the treat. Can believe people are talking bad about this saying she doesn’t remove her hands it’s a freaking dog I think that was pretty great .so negative. That is just too cute and you cannot outsmart a dog cause their sense of smell it 100 times keener than ours is.

Crazy bichon frise lady Sweater

Sweater

Crazy bichon frise lady Tank top

Tank top

After watching it two times I do see how her hand stays on the cup with the treat at all times, so the Dog is watching the Crazy bichon frise lady shirt with her hand on it! He does have a good eye to keep up with the one with her hand though! Here’s the thing though, she doesn’t take her hand off the one it’s under so doggy will always win.