What is the purpose of the Jarl's map in the Dragonreach?

In the Jarl's quarters in Dragonreach (in Whiterun) is a map on a table with red and blue flags marking areas held by the Imperials and Stormcloaks.

I'm still early in the game, so is this map used for some purpose other than the ability to add those locations to your map, perhaps after choosing a side? Currently, clicking on a flag will add the location to your world map.

There are a bunch of these maps around Skyrim. They're basically marking the current territories of the Stormcloaks vs. the Imperial Legion. As you progress in the civil war questline, these flags will change color as regions are captured.

They're basically are a visual representation of who's "winning" the civil war.

As Raven said, this show the progress of the war. As a side effect, you can use (I mean the "Use" action) the pin points to update your map with the most important strongholds and city.