I think Lupita is fit and and attractive and not boyish at all. Troy you used the word voluptuous... Serena Williams is voluptuous and athletic. She has larger breasts and a larger butt, which is associated with womanhood obviously, but you also hear people say that the Williams sisters look like men in drag. The common conception of Blacks it seems is that fitness and healthy body shapes are less womanly and more manly. Hence your opinion. The sister just has small breasts and let's be real White people do not like small breasts (unless you are referring to fashion only where they want small frames so clothes can hang like on a hanger)
Like you said though that is personal preference. The former athlete and coach in me admires women who are physically fit. Most women who are really ahtletic tend to have smaller breasts (by default because the fat distribution is different for athletes). I think that idea of "boyish" is what stops a lot of Black women from shooting for more athletic and physically fit bodies. I mean I've heard women say, "I don't want to look like a man." Which is directly in line with the idea of your "Lupita is boyish." I simply think she is small and while you state that she is what White America finds beautiful, that totally overlooks Queen Latifah as a cover girl spokesperson (an especially high profile spokesperson).
In regard to skin, I guess because when I worked as a teacher in San Diego my Sudanese and darker students very rarely had acne problems and they had issues with hygiene (I say this to establish that they didn't have the best regimen for skin care). Those genes were strong, but so was their dark skin. While my lighter skinned Ethiopian students had acne problems.
But darker skin is less prone to acne. I haven't researched this, but it is true. here is an article that discusses skin types: http://www.crutchfielddermatology.com/treatments/ethnicskin/doesskincarevarywithskincolorandtype.asp#.VQrkLI7F-So
I do agree that people spend a ridiculous amount of dough on hair and beautification products, but that's okay. Our appearance is the first thing we are judged on so it makes sense. Unfortunately, our community, Black people, we just have a lot of history that I still think has been shaped by our grandparents and parents about what beauty is. I guess all cultures have this issue. It's the idea that a dark skinned Puerto Rican reserves the right to claim his race as White on a birth certificate. White is right and this is never more evident in the south than when a woman cuts her hair off and goes around older Black women who all say that women with short hair look like men and must be THE gay.