It's wearing a visor upside down, as if trying to catch rain water.
I wonder if you can trace it back to fast food resturants.
I can imagine an urban teen being given a visor and taking the stance that, ' if i have ta wear it, i might as well wear it my way '.
I once worked at a hotel that had a dance club that attracted a largely black clientele. Most of the men dressed to the nines and DID NOT come in the hip hop clothing that I see white kids wearing when they go out.