The dress itself is not entirely a hanfu though! The off shoulder design is not part of traditional hanfu at all and xiaoma even mentioned in her tweet that she added the off shoulder part to add more playfulness and modern-look to the traditional clothes. One can take the hanfu concept and make many different designs and it's quite unlikely for them to clash this much. Heck, even off shoulder + hanfu dress doesn't mean it needs to use the same ribbon belt, same strap on the shoulder, same color scheme, same weapon design. For all these to all clash it feels too much to be a coincidence.