It's from a Jimmy Kimmel sketch from the 2nd Jan 17 episode, though after a little bit of digging, I'm starting to be a little unsure if this is really Cecily or not.
It was posted as so on SuperiorPics, but if you watch the rest of the sketch and check the credits online, I don't believe it's her. It's also just a very strange, tiny, and uncharacteristically revealing role for her to take.
