Not just an aesthetic 'from the outside' thing that could be interpreted to be a stylistic change and nothing else (IE., the 'giraffe-class Star Destroyers').
No, they pretty clearly re-interpreted the 'sensor pod' on top of the GR75 as its bridge - you can see from the perspective of the shot, here, that the crew is DEFINITELY in that pod on top:

...and especially noting the room as they pan around it when taking damage (last shot, there)...
That pod on top is pretty clearly *at least* as large as the Millennium Falcon's cockpit.
This makes the GR75 *considerably* larger than the model we currently have for it - at present, there is no way any crew could possibly fit up there.





