I always interpreted the physical faces as a sort of magical crutch. Once you mastered the craft you don't need the physical face. Which is why they were able to use Arya's face during that suicide by poison scene without flaying Arya's actual face.
I have been enjoying this season so far, flaws and all. That was until this episode, I finished it, and I felt like I hadn't watched a GoT episode. It's not even the ridiculous plot lines and inconsistent time/travel, it is just an overall change to what the show is, it is starting to feel like just another crappy super hero movie. The one part I did like was Arya talking about Ned watching her from the balcony when she was shooting the bow and her not noticing. LF and Sansa were watching her from the balcony when she was dualing with Brianna. My hope was that they were hinting at the fact that Arya's perception has increased a great deal since she was last in winterfell, and she is in a sense wearing an Arya face as she determines who's name should be on her list.
