What is the difference here? Why did Cell not look Power Weighted the firs time he went buff? Did he mix Piccolo's giant form with the mass increase to create Power Weighted Cell?
Maybe he's Power Weighted because he turned Buff while in FP? I mean he was holding back a monstrous amount of his power against Trunks and Vegeta. I see it as the Buff form against Trunks was just a ''taste'' of what he can really do.
But if he went further he'd be even more Buff than his Power Weighted form. They look kind of similar imo, Power Weighted is just way larger and has a different facial structure.
The different face could just be, maybe to over-the-top comically show how enraged Cell is. I think even Freeza's face kind-of started looking a bit different once he went 100%.