User blog comment:Miskos3/Fairy Tail Episode 180: Garou Knights, Review/@comment-178.148.168.171-20140503121051/@comment-7418318-20140503203129

There's also the matter of the point at which one episode ends.

They can't just animate away and then cut off at the point where the 25 minutes are full. If there isn't a good point for a transition to the next episode, they have to fill up some time to make sure that the next best moment before that is pushed far enough back so it'll be at the end of the ep.

Sometimes this is done by moving flashbacks forward or backward a chapter or two, or turn a scene that was shown as it happened in the manga into a flashback in the next episode (Magi season 2 did that a few times), or you can extend existing scenes.