Right, direction is given in "degrees away from the current direction of the sun", where a dance directly opposite gravity (up the comb) means "towards where the sun is now". It's even better than saying "East" because all of the bees have an internal sun clock and know where the sun is even when they are inside the hive and cannot see it. There is no reference to the hive (i.e. they are not saying "out of the hive, take a left at the pine tree...."), so rotating the hive will not confuse them.
They have run experiments delaying foragers from leaving after they have followed a dance, and in both cases bees correct for the sun's movement over elapsed time even though they could not see it. When a bee dances for the same food source multiple times over the course of the day, the direction of its dance slowly rotates to always give the correct angle with regard to the sun.
Of course they don't "see" it the way we do, but that's not the point. Bees are pretty simple, neurologically, and are so different from humans that the same categories often don't apply. But in the particular fields important for bees (like vector math, aerodynamics, and the traveling salesman problem) they are effectively brilliant. Often much better than humans or even our computers.