It doesn't describe the attire of a harlot at all despite the literary genre, and, despite the genre, if that kind of attire didn't exist, or the reader had no idea what would generally characterize that attire, the verse would be meaningless.
But it can be used to counter the arguments against nature that say these things are only in the mind and not universal.
Doth not even nature teach you?
It's like the verse in the same literature that says God hates a proud look with no description of what constitutes a proud look. The position of one's brows, the tilt of the head, the shape of the mouth, etc. But everyone sure knows it when he sees it. And he knows it by nature.
We can drop the pretenses when it comes to the character of one's clothing. Two indisputable and universal things about the 'attire of a harlot': It's designed to catch the eye, and to allure. And everyone knows it when he sees it, and he knows it by nature.