I think it's just a fun gimmick. Like when they divided reddit into the two the "armies" - periwinkle and orangered.

At first I had doubts whether it's an actual representation of mouse clicks, or if it's just simulating the data. However it does appear to be making API calls in sync with the number refreshing, and the participant rate of change increases during peak hours.

Also, my bad if this suggestion came off as patronizing. I realized after reading How hubski works and how we plan to make it better the amount of thought that has gone into hubski.

Does that alert the user to a post when you link their name?