Looks completely water cooled, not hybrid. I'd guess because air cooling can't manage the GPU and HBM being so close.
The design is nice though. Definitely better than the 290x red weirdness.
I can't wait to see the air cooled version. If the rumours are true not all 390x will be like this so theres still that.
I don't think it is a completely water cooled setup - there would be zero reason to have a full shroud and a rear vent. It's possible, but seems unlikely.
Ultimately, I think this is a fake tease - it seems too short, but I guess if a lot of the PCB space where memory resided is now used for the VRMs and other power circuitry, perhaps it is possibly that short.
It would have to be a very very specialized Asetek pump/cooler setup if it is cooling the entire card without a fan, because all of them are integrated CPU/GPU contact plate and pump, I've never seen an integrated setup that also had additional channels. It's possible, but that would be one heck of a custom order by AMD.
If it's real, and is supposed to be the look of a functioning card, I wonder if there is a fan pulling air through mesh toward the far end, which could be difficult to see in such a photo.
More than likely, it's simply a fake, or was an incomplete render meant to serve as a tease, and they didn't include all of the details for whatever reason.
There are two problems with this post:
1. It's a single rad (no idea why you think this needs more cooling than the 295X2 unless you're in the camp thinking this is a dual card, but even then...)
2. It assumes that this will be the only cooling option. Most rumors point to this being a premium/enthusiast option.
I don't get this. It's a terrible option. If it's WC out of the box, I won't (can't) even think about it - it'll be 980/980 ti only for me. I don't have the room for a 2x120 rad, nor do I want water. I prefer the nice reliability of fans and heatsinks. A lot of people will be in the same boat as me. Many already have a CPU closed loop cooler...
Do remember, that it seems leaked slides so indeed indicate that there is a 390X WCE, and a standard air-cooled 390X. Whether the WCE brings any other changes to the card, save for the quieter cooling, remains to be seen.