If no notes are selected, or if there are no links in the map, all notes are drawn normally.
Highlighted notes are shown in an animated dashed style, with the gaps cycling along the link from source to destination. By Cmd+clicking additional items on the map the number of animated links can be increased, e.g. indicating a path through a set of linked notes. It is not intended as general eye candy: trying to animate every link on a large map may start up the computers fans and/or leave the map unresponsive.
In complex maps, link animation can consume significant computational resources. Link animation is slowed in large maps to manage load.