Super skinny models in magazines and even super skinny mannequins in shop windows make normal women look fat. I personally know a few people who are obsessed with being skinny. They struggle everyday - they literally starve, purge, take laxatives and the weighing scale determines their happiness quotient. They don't care if their body is denied of nourishment and nutrients.
Somehow it's in built in us to compare ourselves with others, including appearance. When women look at pictures, or advertisements of super skinny models and or look at super skinny mannequins in shop windows who are a size 6 or even less (what's that, like a small child size body?!, I don't know...), it dampens their self esteem. It's important to think differently about your body. You don't have to be super thin to feel beautiful. You just have to be kind and caring towards your body by eating healthy, living a healthy lifestyle, get some exercise and have a healthy attitude towards life without following fad diets or taking extreme measures. It's important to have a body weight in proportion to your height mainly for health reasons and of course healthy weight will make you feel good in every way and keep illness at bay.