bendover:
This is a girl who got everything she wanted from mommy and daddy.
This is a supposition you keep repeating, without any evidence. You assume that she's spoiled, which may or may not be true. All we really know is that her mother is supporting her quest. I can just as easily speculate that she got nothing at all from her father, ever, and that's why she craves attention, and particularly the the attention she may get from men with this type of picture. I don't know that this is the case, but it's just as good an assumption as yours. I can imagine (with no evidence) that her mother is supporting her because she feels guilty that she hasn't given her daughter, or been able to give her daughter, other things. Or perhaps the daughter is emulating her mother, which is why the mother is supportive.
I'm also going to go out on a limb to speculate something else - that this 'award-winning yearbook' allows a lot self-expression in the photos the staff allows the students to express themselves with, that the pictures are NOT the assembly-line basic portraits most of us remember being taken for our own yearbooks, which the publication could then easily use to limit all students to a head-and-shoulders portrait photo. Further, in their creative, award-winning wisdom, they probably never thought to establish standards for this self-expression. Not having done so, they cannot so easily make judgment calls about what is acceptable. (Now how's THAT for speculation?)
Personally, I think it IS part of a school's job to provide guidance and set limits for the students that attend, in part because parents don't uniformly (adverb here chosen intentionally) do such a god job preparing their children for the world. And an appropriate dress code is part of that. This is coming from someone who grew up in the sixties and attended a school that wrestled with the issues of proper dress. That being said, a dress code should take into account (though not always bow to) the times, location, and culture in which it exists. In my high school, we were never allowed to wear shorts, even after the dress code war was fought and won, because quite frankly that wasn't a big issue - then. But shorts are more of out culture now. Setting the allowable length of a skirt is reasonable - with the proviso here that the standard when I was in high school (which may have been 4" above the knee) may be ridiculously restrictive today, but may have been scandalous in the fifties. And just as (in my opinion) it's reasonable to set standards for for what may be warn at school, it is also reasonable to set standards (not necessarily the same) for apparel in yearbooks, or attending school-sponsored events. But the standards should be clear, written, and established in advance, after appropriate input from students and parents. That's what happened to end the dress code wars in my high school, way back when. There were those who were sure learning would stop once girls were allowed to to wear slacks and jeans to school (horrors!), and others equally convinced that freedom had failed because those jeans still could not have frayed cuffs. But it all worked.