Unwanted or not, you're guy is still pretty handsome! His cut really reminds me of a modified schnauzer cut...
Finding a really good groomer is pretty hard, and for the most part I find I have to be really really specific to get what I want.
The only time I ever really managed to get a good groom my first yorkie Barry (Winston's hair hasn't gotten long enough for me to worry about this again yet) was when I made the groomer show me how short she felt I wanted it. Brought photos, and asked her to scissor or clipper a small area on the body to the length she thought I wanted. I don't know if this helped so much because I made her think about it while I was there (and therefore she remembered or had a guideline piece) or if it was because it allowed us to both get on exactly the same wave length and there wasn't any misunderstandings.
It generally meant he was never dramatically shorter then I wanted, although it didn't always mean a nicely shaped face. If you manage to find that length you like, be sure to ask what size attachment they used to get it! It will be helpful the next time, because if you tell them what size attachment to use on the body you will get the exact length you want (providing they listen of course
) I am thinking she cut his head the way she did in order to make the head and face "match" since well. Its hard to keep a lot of length on the head and transition it to such a short cut on the body without it looking somewhat awkward. He is awfully short though! Perhaps she simply misunderstood what you meant by short, or just slipped up and cut closer then she should have or created a "hole" when he moved and was forced to even it out.