To me the biggest difference I think is the skull head and forehead. My big yorkie that looks like a silky has a more flat forehead and my little yorkie has the more round forehead. Silky have the more flat forehead and yorkies are suppose to have the more rounded look.
I have a not so good picture but at least you se my example. My bigger yorkie has flat forehead while my little yorkie has the rounder forehead.
My bigger yorkie looks so much like a silky. He is also longer body.
Any way, My 2 cents on the matter.
