Yes that's the Freedom base from Shadow of Chernobyl, but let's not forget that Clear Sky is set about a year or two before the events of SoC, so who knows who's base that place is now in Clear Sky (at least when the game starts). As for the graphics, awesome, absolutely brilliant, and I noticed a good number of changes in the actual base's props/entities/objects and various placement of buildings, it really gives the feeling that it does take place a year before SoC.
The place looks a little more "destroyed" and ruined than in Shadow of Chernobyl. For instance, you can clearly see in that video at some point that one of the sniper tower is torn apart and fell to the ground. But that very same tower in SoC is clean and is standing solid with a sniper on it, surely giving the illusion that Freedom did their best to repair what little was left to repair from those ruins to re-secure the base as their stronghold. It's details like that that makes GSC GameWorld my new favorite FPS developer since last year.