Yes, the article alleges that the dupes are illegitimate:

They simply use Popflex’s copyrighted images without permission, sometimes editing the color of the skort in the photo to fit the listing. In May 2025 alone, Popflex counted 461 listings it believes infringe on its Pirouette Skort design patent, but it’s still a drop in the bucket of the thousands that Ho has encountered just by doing reverse image searches.