This is especially useful, if there are other similar graphics that are not active. What is more useful in aiding navigation is when a mouse-over gives some textual information about what is on the linked page. Navigation aids that are too clever to be understood are useless. The need for movement on a page depends on the purpose and content of the page. A financial institute would not really need animations on their pages, while an entertainment site obviously would have such movement.
Animation can put some life into a flat web page.
On the other hand, too much animation can be irritating and unnecessarily slow the delivery of the page. Sites advertising creative services especially related to graphical design, entertainment, or advertising should have animation to show off their creativity. You have to differentiate between animations and interactions. A mouse-over that displays some text is more of an interaction. In conclusion You should have a reason to put animations on a page.