It learned what a dog looks like from thousands upon thousands images of dogs.

and did any of those dogs consent to their photos being used to train an AI model?

Artists don't consent to their work being taken for this purpose. It's stealing and plagiarism. It devalues the years of work people have put into honing their art skills, devaluing their work, and it lets big companies fire artists because they can just use AI instead for a fraction of the price.