hmm. not sure. maybe those are not 12 week old pictures, maybe they were taken at a much younger age??? they seem a bit expensive, or is it just me?? i don't know, they are cute pups but i am not sure that i have ever seen a yorkie pup that wasn't cute
i am no help at all, sorry. all i can think is that they look very young in the pictures, aren't even really standing up, and if they were lying about the age to make them appear smaller, they would not put the weights as being 4-5 lbs. I kinda think they look like their hair has been cut. At least the ears look like they have all been shaved. i don't know...i'm am a bit skeptical about internet breeders but then again, i am no expert. i would rather refer you to a breeder i know or maybe one from here rather than a random internet site. you just never know...
good luck finding a baby