Er, in the video, watch the seconds ticker on the clock to see when the panel stops redrawing. The NetworkManager icon changing size on connecting to a network (as Josh says) causes the panel to stop redrawing; moving the panel around causes it to start redrawing again.
If a Firefox window happens to be open at this time, it will also stop responding until it is moved, exhibiting similar behavior to the panel in this respect.
Er, in the video, watch the seconds ticker on the clock to see when the panel stops redrawing. The NetworkManager icon changing size on connecting to a network (as Josh says) causes the panel to stop redrawing; moving the panel around causes it to start redrawing again.
If a Firefox window happens to be open at this time, it will also stop responding until it is moved, exhibiting similar behavior to the panel in this respect.