The shower hand sprayer is kind of on it's own compared to all the other plumbing fixtures. With its position here, you can sit on the shower bench seat and get pretty much reach whatver bits and peices you need to soak or rinse. The head is adjustable so you can set it to soak, spray, and massage.
Not only that, but this sprayer, bench seat combination makes life a lot easier when it comes time to give the dog a bath. No more lifting the big heavy dog into the bathtub and bending over to was the dog. The two of you can get in, sit down, and get to washing.