For some information in the event list of the Place View or the Single Person View, there are more details. In this case you see an Info Icon  , e.g. here:

 if you move the mouse cursor over this icon an Info Box shows up, in this case with a short, simple note:

(You need not use the left mouse button.) Moving the mouse cursor away from the Info Icon makes this Info Box disappear.

In some cases there is more complex information such as a link or pictures:

These Info Boxes stay open permanently, they do not disappear when the mouse cursor is moved away from the Info Icon. In this case, you see a cross in the upper right corner: To close the Info Box, just click on this cross.

In the case shown here a click on the link will bring you to the Street View.