Basically, what it does is it removes the need to go through the ratways all the time to change your face.
Now, of course, to do this you can't just say: "move to my house, WENCH!"
Instead of that, you need to pay the sculptor A LOT of money to cover the expenses for the other potentional customers of the face sculptor.
If you have got Hearthfire, you can place her in your basemant if you want to keep her hidden.
(again, I thought this would make a nice asset so you don't need to go through all the loading screens before you can change your look)