There is a door. On the other side of the door is a bar. Previously, there was something else on the other side of this door. The bar does not consider this especially relevant.
Asatyyl, the being who has just found himself inside of this bar, might notice several oddities about this bar, beyond just its sudden appearance. Such as that it contains no bartender, and at the moment, no customers; or that there is a window displaying a frightening yet alluring view of galaxies' worth of stars exploding in vast supernovae, or that the bar appears to be decorated for Christmastime. There are trees adorned in ornaments and lights, as well as what appears to be snow falling from somewhere that is not quite the ceiling, but is not identifiably any other location.
Or perhaps it won't be any of these things that he notices. He's not human; he comes from a universe that may have different expectations for would be out of the ordinary. Most of the multiversal guests at this bar, though, quickly find quite a few expectations subverted, whatsoever they might be.
So what does Asatyyl do, when this bar appears in his doorway?