1) To distract from the dripping tap.
2) So that mikveh dippers can time themselves to make sure they don’t take too long to get naked.
3) To make the changing room reassuringly haimish, like a bedroom.
4) Really? A practice dunk is totally normal but having a clock in there is the weird part?
5) To remind dunkers to get a move on, because the rabbi doesn’t have time for this crap. There are a lot of other women waiting to practice.
6) Maybe they want to turn on the clock radio and play some tunes they can dance naked to. That could be really fun.
7) To distract from the hidden camera teddy bear, the hidden camera photographs, and the hidden camera cunningly disguised as a slightly larger camera.
8) Just to wake up visitors in case they came straight from Bill Cosby’s place.