Because the vase is just a scenery, and the scenery is just for appreciation, or it refers to a good figure. Some women can't say that they are vases at all. They are thin without breasts and hips, not slim. Of course, when you say lose weight, you mean a woman who is too fat, either elephant leg or bucket waist, which is unattractive. Women should be slightly fat, with moderate breasts and hips, not too thick arms and legs, and not too thin waist. Therefore, it is called one of the four beauties. Fat is first of all visually sweet, and then the sensuality of contact. Men like women to be feminine, just as women like men's masculine keys. This is the simplest gender complementarity, not just sex. Men like thin women because they are weak and petite, but those are not permanent advantages.