It is a legendary battle arena. Its employees are renowed for their prowess, and would likely do well in the brutally war torn setting that is warhammer 40k.
Technically she DID also punch a customer a bunch of times earlier in the full video but that customer started shit at Waffle House of all places, so that's on them 🤷
40K Warhammer or whatever that minifig painting competition is called was asked to design one of their battlegrounds as a waffle house as there were a lot of fights irl in such fast fat restaurants.