Mrs. Beautiful, the business about flashy is exactly the point. Many people would say that shortening the skirt to get rid of the slit (as someone suggested) is 100 times more flashy and far worse from a tznius point of view. We really need to leave our opinions out and follow what the halacha says, which is that the knee and above must be covered at all times. Anything else is a pure invention of the person making the statement, reflecting his or her own personal fashion tastes. We simply cannot have halacha based on subjective opinions.
My daughter once brought home a camp list saying that the zipper or the pockets were forbidden or had to be only in the front or only in the back, and I don’t even remember which way now, since it was so arbitrary. I actually aggravated my daughter telling her some of her skirts were improper, and should now ask mechila, since after researching the matter, there was nothing wrong. It was just a figment of the camp director’s imagination.
Same thing with my son’s clothing guide for yeshiva saying that bobby pins were forbidden. I firmly believe that if we would put in half as much energy into following real halachos as into imaginary ones, moshiach would have come already.