Mysterious— I cannot see it at all. It used to be there all the time, not only hovering over it.
Perhaps the reason is Adblock? It has a VERY long list of blocked images, mostly imported from Dutchblock (I think… I did not ad them), including wildcards such as “stats”, “counter”, “tracker”, and so.
Or, perhaps the reason is thatI emptied all cookies and temp files recently?
However. no fuss… it just looks a bit funny with a “statistics” headline and then, nothing.