I had two inspirations in mind when I designed this bathroom: 1.) The prompt from the contest, birds bathing. 2.) The Garden of Eden (hence, the plants).
I added a little wading pool for your feet (we all love to splash around and jump in puddles and lakes, rivers and streams... So why not add a little of that in there? Like bathing in a stream in Paradise itself... Plus, the water element ties in with the theme of the contest: birds bathing. It's like a birdbath filled with water--but for humans.