Basically, it would appear that they've taken the bridge and scanner/sensor array domes and "supersized" them in relation to the overall size and proportion of the ship, and then (again if what we've seen in the trailer, and Vektors "accurate as far as anyone can tell so far" attempt at matching) abandoned the "philosophical" rational for them being what they were before.
I'm really hoping that we won't see this done this way in the film... because it just MADE SENSE that the "bridge dome" contained the BRIDGE... and just the bridge. At least, it did to me. Having it be a "pointless kewl shape" as it would APPEAR is the case now is... well, at best it's a little annoying. Again, IMHO.
It's not the SHAPES, exactly, that I care about... it's the LOGICAL FUNCTIONALITY of the design. If what we've seen in the trailer is accurate, they've abandoned that and THAT will annoy me.
On the other hand, if the idea is that the B/C deck superstructure "used" to be only 1 deck thick (Pre-TOS) (making the p-hull only 10... or even just 9... decks thick instead of the TOS-established 11 decks)... THAT I could live with, I 'spose. It would establish that between the time the did this and the time we first saw the ship, they rebuilt the B/C deck superstructure entirely (which isn't unreasonable for a refit) and added some overall height to the design in the process, but left the saucer structure itself unaltered.
Again, I'm HOPING that the ship we see in the film that's supposed to be "our" Enterprise is actually that ship. If there's an alternate reality version, well... in THAT case I can deal with it being pink with green polkadots and 2000 km long and wouldn't blanche...
... as long as we end up the movie back in the "real" universe we all know, and MOST of us love.