@Draco Dei
Rainbow Dash is just doing the laundry. She doesn’t need to shower herself since she’s already bathing (in her sweat).
The reck wasn’t always levitating. It used to be mounted on the bathroom wall, but I told AI to remove the walls since it made no sense why a cloud would be indoors.

I mean… Setting up a public wash-station for weather-ponies could be reasonable if they need to shower during/after their shifts. Kinda confused why they would need to do so with clothes on, but if it sweaty wicking rather than rubber for maximum smoothness and thus streamlining, she could be just laundering it while still wearing it prior to taking it off to scrub her coat. So-casual-they-never-think-about-it (1) nudist culture has some weird results.
(1) Except when AJ points out the irony of Rarity not letting Spike into the room when they are getting primped for the season one Grand Galloping Gala.

P.S. The self-levitating soap-and-shampoo rack obviously is a good portable design, especially for Pegasus who may want to park it above cloud level so the soap doesn’t get on the ground and waste itself while also creating a slipping hazard. [Tongue in Cheek]There is absolutely no possibility what’s of ever it is simply a generation error.[/Tongue in Cheek]