Of all the tiles that have the translucent bluish animation, they are using one animation object. This cuts down significantly on update costs. Instead of having to update 50 animations (lets say for range highlighting) and hope for them to keep in sync, you can use one animation and reference them from more then one actor.
In this case however we have a total of four actors on the map. The cursor, Person, bush, and highlight (sharing the same animation as the cursor). There is only one highlight actor, but he's attached to the map in 9 places. While you wouldn't want to do this with actors that you want to activate an event on, it works great for engine handled graphics.
So by seperating the tile, animation, path and picture classes, we can attach each of these to more then one place at a time, without more overhead (besides rendering... which I have to admit is the biggest pull back to all of it)
:: EDIT ::
I thought that I'd start posting my line count...