As stated above, the princess gimmick was created for humor. The joke may be tasteless, but that's all it is. There is not some underlying anti-fat agenda going on here. There is also a difference between fat and morbidly obese which many people seem to be missing. If you look at the picture of the princess she isn't just "fat," she's unrealistically obese. If I see a cartoon character with such a large nose he can't get through doors without knee-slapping antics, I'm not going to cry anti-large-nose.
Political correctness is a nice little idea, however if I see a 500 pound anything walking down the street and complaining about their current state I'm not going to give a rat's ass about PC. I'll be appalled or irate. I'd love to hope said weight is actually just concealed muscle mass, but that's just not how it works it in the world most of the time.
Besides, why are obese people now untouchable? Society heckle smokers, potheads, heavy drinkers, etc only a daily basis. What's the difference? "I was born this way!," I hear cried. "It's genetics, not habits!" I'm sorry to say statistics are not in your favor. Besides, have you heard of epigenetics? Based on outside influences genes can turn on and OFF, become methylized. That's right! Not only that, but these "on" and "off" states can become hereditary. Anyone who decides to destroy their health or not actively seek to better it can in effect actively spite their children's and grandchildren's health.
Whew, I do apologize for the full blown rant, but I've had some excess bile build up from all the posts I've read. Despite what it might sound like, I'm not trying to preach the perfect life. The point I'm trying to get across is take more responsibility for your self (maybe we need a little more existentialism in our modern philosophy) and get over it if your every quality isn't portrayed in a positive light. The truth is it never will be.