Why does Sora no otoshimono have different ending themes per episode? I've finished watching the Anime's First Season and I noticed that every episode in the anime has different ending themes.

As you can see in this list of episodes. Heaven's lost property has different ending sequences and different ending themes for a 12-episode series anime. Is there a significant reason for this?
It has different endings because they are after scenes for each respective episode and shows what is happening after each episodes misadventure.