You make interesting points Celia. Looking at the cover it seems like they did slim Masha down especially her broad shoulders.
Alot of people keep saying how thin Maria is. But I don't think she's as thin as most people think. I think Maria Sharapova stands between 6'2" and 6'3" tall and weighs about 175 pounds. Goldenlox who is a girl and an expert on the female physique thinks Maria weighs 180 pounds. Masha has gotten a fair bit thicker in recent years as her untampered with photos prove. But because she's so tall she still looks slender to some people and especially when her photos are fixed to make her look thinner.
Maria is tall and long limbed, which can make her appear somewhat gangly at times. People misinterpret this as her being "too skinny", when it's fairly clear that this isn't the case. Her muscles are fairly well defined and she appears to be in very good shape for her physique.