The monitor by the darkroom entrance in the AV room shows that a camera is panning, zooming, and following Tiffany throughout the scene, although it's supposedly coming from a stationary camera since there's nobody else in the room that would be operating it.
Just before Tiffany stands up in the hot tub, a flesh-colored body-wrap on Danielle is visible above the waterline and is visible again at the end of the scene as we see all three girls standing in the tub.