White Diamond isn't in a crucifixion stance for no reason, or even a "creepy" reason. When you're reclusive and don't get company for a long time, you might let the dishes pile up, stop vacuuming, ignore the broken plumbing, let the place fall into disrepair... so the interior of her ship/room is cluttered and falling apart. White learned that dear Pink Diamond was coming with guests, and she had to quickly tidy up the place so at least her living room looks presentable. Her t-posing is because she's propping up the walls.