He IS cute
, but I will not be surprised if he is not 100% yorkie, because of his legs. Not a very typical for yorkie type, IMXO. Sometimes mixes look like purebreed...
I saw some dogs who are mixes, but look like standard breed
Or it can be just poor quality yorkie. Don't get offended, he is still cutie, I am talking about breed STANDARD ONLY. But his hair color/texture, face... it is all about yorkie