My reading is that when the door's closed you don't need the sign at all since if you can see it, you're already in the blast room. The left-pointing arrow seems like the better way to do it to me, when viewing the open door from the hall (though either is probably perfectly clear). The two sites being built by different contractors seems enough to cover the differences in painting/finishing touches (unless there's a standard open/close direction for vault doors, I wouldn't know :) ).

But then, "raytraced" never occured to me looking at the photos, just "taken by an actual good camera, not a phone, with a fast lens so that it can take good indoors photos without flash."