When it comes to sexual attraction, no part of the body is excluded. To most straight males (and gay women I guess) feminine shapes are usually atttactive, that can include boobs, hips, noses, hair, ankles. Are female ankles different from male ankles? Difficilt to tell, but a feminine ankle will be probably attractive to someone attracted to women.
The whole cultural thing is absolutelt present, but not in the fundamental attraction for female (or male) appearance
Technically it’s not, practically it is beacuse we all live on constant gravity. Except in planes and jets funnilly enough because sudden and great acceleration do make things inside the plane weigh more or less even if their mass is the same.