Baffled in the bathroom

My room here at the lovely Hyatt Columbus is fine, albeit one of those reduced space, triangular, corner rooms comp'd performers are wont to get. There is no tub, just a shower, also not unusual, especially in rooms of this type.

However, inexplicably, my shower features a nearly useless 'tublet' capability. There's a fancy stopper, a fill faucet, and an overflow outlet, just like on a big tub. I guess you can fill it up 3 inches and...what? Soak the bottom half of your feet? Commit knee ablutions? Dampen your taint? Curious...