“Can someone please explain the reason why a girl might be struggling to dress tznius?”
I cannot speak for other women, but personally here’s why I struggle:
#1-I am grateful for the side benefits that Tznius affords every Jewish woman aside from the schar mitzvah. Really. But the fact is that appreciating Tznius doesn’t mean that I appreciate the standards that halacha demands of me.
It takes a lot of effort and honest self evaluation to get to a point where you truly appreciate those standards. Until then, you remind yourself every day that your job is to make Hashem proud even when you don’t (yet) appreciate them. And you tell yourself that YOUR standards shouldn’t matter, only Hashem’s do. Even if many people dress worse than you.
#2-I don’t dress to attract attention of others. I don’t dress to impress friends. But I am still a girl who will stop and stare at the pretty flat in the display window. I will critque perfumes with my friends for fun and Sephora is my personal disneyland. And yes, I can see a pretty blue dress and know it’s too short & tight for me, but it is still a pretty blue dress.
I understand that to the opposite gender this dress will turn me into more of a physical object than I’d like to be. But it’s still pretty! The same thing goes for the skirts that hit mid-knee. It’s as wrong as anything, but you’re not gonna get me to say that the look isn’t simply adorable (on the right person…).
So even when you’re willing to follow the halachos perfectly, it’s hard every time you see a cute short skirt or much-too-tight-but-so-so-pretty dress. It’ll never make me less of a fashion enthusiast.
I hope that one day I will be strong enough to overcome those challenges despite the difficulty. Until then, I struggle.