If you’re connected to politics in any capacity, just do not under any circumstances hashtag the designers you’re wearing and then attack your critics on Instagram. Not only will you generate ugly media coverage, but you’ll lose the support of the designers.
To return to the OP … the link led to an article about Mandy Moore on a red carpet somewhere. The things she was wearing were given (or maybe lent) to her by the designers at no charge. In return, she tells everyone who those designers were. She’s aided in this task by every interviewer starting off with “Who are you wearing?” That’s how red carpets work.
To me, stuff like
sounds more like what you see in glossy fashion magazines accompanying photo shoots. So the mag’s stylist buys (or borrows) certain items and puts them on the star for certain photos. They know exactly what the star is wearing because they put those items on her/him.