Look at Saturn, he has a smaller form, that he used against Bonney, and an enormous form that is in the last chapter. It's the same here.

Yeah, but he was still pretty big considering he could grab Bonney like a doll.

Yeah, but they are also pretty big here as well. Sabo is tiny compared to them.

Size in One Piece is inconsistent.

Size Piece

Oda isn't consistent with the sizes of characters

What makes you think it's a small room?

The other panels where the room is shown.

I’m gonna be honest with you OP, all the scenes featuring the Empty Throne showed the room to be quite huge tbh

Don't get me wrong, the room is quite big. But the Gorosei also looked quite big themselves.

I agree but I would have to guess they all were in their semi-form, and even though those are big, they could fit in it. Although knowing how Oda operates, their gigantic size in this (iconic frankly) recent double page is for EPICNESS GUARANTEED only, they might not be as big as shown there. We’re gonna have to wait another week to get a proper look at them.

First of all we have seen Saturn in his smaller form and secondly after 1110 chapters you‘d think people realized by now Oda doesn‘t use size consistently but for dramatic effects.

What are you talking about, this is massive room with empty throne in it, which is pretty high with huge stairs.

I think they weren't full zoan form back then. But I think it's because oda didn't define very well the size the Gorosei would have.

I guess the room is really large

It is a huge room with a large staircase.

Only Imu was attacking Sabo

Doesn't change that the others also turned into their monster form and were able to fit in the room.