Really like the tone of that pic. It's CG indeed, so my first thought was that they're releasing a CG short film or something. But I can totally see a story trailer, combining both CG and in-game footage, hopefully. Don't care about them showing things they haven't shown so far provided they're not super spoilery.
That pic is super interesting, though: Noctis, all by himself (no chocobros in sight), seemingly relaxed in what could be Niflheim (that skyline doesn't really match Insomnia's (even when destroyed), and I'd wager that all that smoke is a consequence of heavy industralization rather than, say, an invasion) and not giving a shit about all those Nif ships.
Also, there seems to be a sea there (which could perfectly mean that that's actually Imsomnia, mind you, but I'm still betting on Niflheim).
BTW, we don't even know what the actual name of Niflehim's capital is, right? We know that Lucis' is Insomnia and Accordo's is Altissia.
I'm already seeing people (not here. You know where, lol) getting themselves WAY too hyped about this "make you lose your minds" thing. Completely convinced themselves it's something more than the trailer, like a new demo or multiplayer or an earlier release date.
These people are insane. I swear some people just can't handle their overactive imaginations. We're gonna get a cool trailer. That's it. Don't wanna hear from anyone tomorrow complaining about how that wasn't mind-blowing enough.
I don't even know who would want a demo when it's only a month, tbh. Two months ago, when they announced the delay? Ok, I could totally see it. But now? Hell, no.
I don't think it's going to be a CG short film or anything like that, just because the "Omen" hasn't been stylized in a way to make it look a like an actual title, like KG or Brotherhood (very silly reason, I know). I'm betting in that being the name of the trailer, à la "Dawn" and "Reclaim your throne". Hopefully more similar to the latter