I think this issue reflects vividly how the GB and JWs (and on some extent christianity but it depends on which group you are dealing with) when it concerns gender. If women were depected as wearing slacks or jeans then it would muddle the land of what is masculine and what is feminine, which then could reflect who was in control of what. When a woman is depicted in a skirt or dress, it kinda always depeicts this submissive wife, maternal figure. In illustrations, pants would signify a type of control 'she' (in general) had that does not go with the watchtower's beliefs.
I remember vividly being younger and being black, my hair is not typical of that of the average white guy (i know, duh.. but im going somewhere with this) In my predominately black hall, I was always counciled to keep my hair in a shirt fade (very close cut) when in reality I HATEd haircuts (and on some level still do) and liked mine to get a little height to them. it was never an afro or a bush, but it was.. hair. I was told to look to the depictions of the watchtowers of brothers who was brothas as to how my hair should be.
But I didn't want my hair like that. in my predominate white hall, it wan't an issue because they didn't know anything about it to make it an issue.
So, in the end, these pictures have a point to them. 'Women' should be in dresses, even when doing work to reflect their femininity in that classical 50's rigidness that doesn't reflect our world, but rather that of men's fantasies. Women in dress like that usually aren't telling their husbands their disrespectful brutes. Women like that cook and are always beautiful. they don't like.. fart or get mustaches and act.... You know human.
And as to what another poster said, the reflectin of men isn't that 'realistic' either.