So you're just talking about the look of the car? Because BYD has been doing EVs far longer than Porsche, so if anyone is doing a rip-off of the tech, it would be Porsche.
As far as design goes, BYD's aesthetics in recent years has a lot to do with them hiring big-shot European designers like Wolfgang Egger. If they're pulling from the same talent pool as other top carmakers, it's not so obvious why you'd accuse BYD of copying others, and not vice versa.