Wait... she's had two children and she still looks like that? That's pretty impressive.

Unlike what many seem to incorrectly say, Bin Woo is now of a healthy weight. So she is not "anorexic" - that's a completely hyperbolic exaggeration. That picture of her collar bones is due to the camera angle and her emphasizing them. That first picture of her shows a fit woman. Nowadays so many are overweight that people have lost all perspective of what a human body of healthy weight looks like. Excess layers of fat has become normalized. Human bodies are the product of millions of years of evolution in an environment with little to eat, so they became adapted to surviving on little nutrition, and being quite thin. From a physiological standpoint there's nothing necessarily wrong with having a body which lacks "meat on its bones".

Having said that, what's worrying about these Korean celebrities' weight loss stories are the methods which they often choose to achieve their goal weights. The methods are quick and rely on extreme changes to the celebrities' diets. The only focus seems to be calories, while nutrition seems to be ignored. The weight comes off quickly, of course, but it's not good for the body, and it's difficult to maintain a weight which is the result of a crash diet.