Celebrities are known for their elaborate fashion wear on a day to day basis. Even once they have made it into the Hollywood status book they seem obsessed with having anything but top label items.
Whatever the reason if it's a celebrity wearing it even if it's a pair of sweats you can bet there is a big name label hanging on the tag. The competitive world in which stars live is very hardcore, as even if they be friends with each other, they are well aware that they will be rivaling each other for the next big role in the next big Oscar film.
Most celebrities are labeled from the top down, even through their sunglasses and undergarments, just in case. If you are a celebrity rather you care or not, you will learn fashion soon enough.