My impression of what happened is that Hatate stopped using her Thoughtgraphy, switching to a conventional style of reporting sometime after the current age of gensokyo. Time passes, and she remembers that she used to be able to do it, and decides to try again. In doing so she digs up a photo of Marisa and Nitori, and then goes and shows it to her. Nitori thanks her, and Hatate realises that her ability isn't as useless as she used to think. She goes and talks to a still alive sanae about the outside world, having remembered seeing photos of it with thoughtography. Eventually Aya visits her, they talk about gensokyo past and how the new shrine maidens are useless compared to Reimu. Hatate then writes using her thoughtography with the lessons she's learned, and rises above Aya. Aya admits that she's getting too old for this, but still wishes to beat Hatate next year anyways.
