an animal painted painting could absolutely be more artistic than one done by Pollock. Dogs are supposed to have a very limited color recognition some breeds may have a little better than others but I once saw a Huge great Pyrenees at a carnival wearing painting booties walk on 3 legs holding up 1 paw then go over to a canvas it was painting? sit on it's haunches then smear some paint in 1 direction then another then place its paw in another color smear that then keep selecting other colors. eventually it had painted could be loosely called a the dog and the tree although it required a stretch of one imagination.
TRAINED to do this? if so how? Plus how could it tell which colors as it appeared to randomly selecting them returning to places it had missed to add more of the same color it had previously applied. A neighbor owns a Pyre he has had it for several years and says as a pup while he was trying to train it that it was the most stubborn animal he has ever owned but one of the best heard dogs he has. his kids used to ride it when they were very young
I think that a Chimpanzee might actually be aware of what it were painting if one was trained to do so.
But some humans having the awareness of what they are doing while splashing, dripping, smearing, or dumping paint on a canvas may be questionable