When we first see White Diamond, she is maintaining a very rigid position (the notorious T-pose), and doesn't alter her position at all. At least several days later, she is still in the exact same position, and it's implied that she hasn't moved for a much longer time than that. She only finally moves when she's highly emotionally perturbed.
However, it's not clear why she's doing this. To start with, White Pearl claimed that White Diamond had more important things to do than attend a ball, but she seemingly was doing nothing. Further, she didn't seem to be rooted in one place out of pure apathy, since she still acted through her Pearl or spaceship. And while it's true she didn't want contact with the other Diamonds, that doesn't really explain being perfectly stationary within her ship.
Later events make it seem unlikely that she was actually doing anything crucial by standing in place for so long. (nothing fell apart when she moved, say). Finally, she seemingly can exert control over other Gems and move herself at the same time, so that's not it either.
Why was White Diamond standing in this pose for so long without moving? Was she actually doing something?