She got soooo ...big!
Don't get me wrong, I think she is still a beautiful woman, but I can't believe she looks so much bigger in Once Upon a Time than she did in House. It's not just heavier, but taller, larger boobs (probably fake) and just a bigger bone structure - almost amazonian.
I just started watching the first season of OUaT after re-watching some earlier House episodes where she looked almost too thin, so maybe that explains the dramatic difference.
In House I thought she was one of the most naturally beautiful women I have seen and she still is quite hot, but she looks like a different person.
I also like her much better as a brunette.