Re: Game of Thrones: Season 3. TV Series Discussion. NO BOOK SPOILERS...NONE
I think they did that ending in an attempt to have it finish on an uplifting note after the despair of episode 9. I would have preferred if they kept the Arya killing scene for the final shot though.
Have the camera slowly zoom in on her as she's looking at the coin after slaughtering that guy, then she looks up with murder in her eyes, staring straight into the camera, says valar morghulis, cut to black, roll credits.