Completion mark

Today I’ve glimpsed that when I finished a video on the screencasts, it has a grin completion mark.
However, after reviewing the video again, and moving on, I could not bring brak this green tick that brings me such satisfaction. Is there something that messes with it on my end or its a bug?
I couldn’t bring it back. Refresh, restart, cache cleaning…
Can someone hint me what I’m missing? Its quite motivational, when you are going through it to see the completion of the whole screencast.