What do the two small white dots in Clock app - Stopwatch do?

Thank you.

I can see when you swipe left or right to change the display, that the two dots do update correctly.

Swipe left to show analog clock face and the right dot highlights and left dot diminishes.

Swipe right to show the digital clock face and the left dot highlights and the right dot diminishes.

So that seems to work properly.

However when you tap on the two dots, they swap highlighting as if they should be controlling something.

But the face of the clock does not change. This appears to be a bug.

The two dots in the clock app do not function like the little dots on the home screen where if you tap on the dots it cycles through home screen pages.

Or like in the camera app where tapping on the labels (time-lapse, slo-mo, video, photo, etc) cycles through the camera modes.