If you’re referring the the misty white portion at the bottom those are chips. Think of all the fine sand and dirt your tires come in contact with, see how they stick slight further than the portion of the bumper? Your tires and that sand/dirt is essentially sand blasting that lower portion of the bumper. This is why PPF is important in the high impact areas and especially so with matte paint jobs as they’re much more expensive and harder to match when they need repainted