It suggests to me - and it's easier to tell in the actual video - that the ship is around 150% of its old size of ~1000 ft. In other words, about 1500 ft long. The rim of the saucer seems to be about 2.5-3 decks thick, based on the welder guy on the rim. You can see him in the video, in the still image he just looks like a black dot.
It's hard to tell, but I'd say that down to the bottom of the black port under the bridge is about 2 decks, which lines up pretty good with the 150% guess.
Of course this is not a real image, but a collection of CGI models, so who knows how well they bothered scaling it to begin with.
One thing that's very interesting to look at is this image, compared to the image of the Kelvin we see in some of the "official released" images.
In particular, look at the small amount of the nacelle (obscured underneath) and the bridge module. I haven't done a line-by-line breakdown, but the two elements look, to my low-resolution uncalibrated first glance to be identical.
The saucer shape also looks identical, with the exception of the "tier" with the weapons pods in it. I'm referring, in particular, to the shape of the "superstructure" under the bridge, and to the curvature of the saucer cross-section, in particular.
I had someone I know who works at ILM (but is NOT on the Trek team) tell me, a couple of months back, that the ship we saw in the trailer was a "hack" done with elements of the Kelvin. I've never known whether to believe that or not, and I still don't. But what I've seen in these images does tend to support his claim, at least a little bit. Or rather, it doesn't CONTRADICT his claim, which is what I was looking for. If it contradicted it, I'd know for sure. As it is, I still don't. But I'm more inclined to believe it now than I was before.