I think it did serve a purpose, if you watch it in chronological order it all loses it's surprise, besides, this show isn't about "Watashi" but about seeing how she interacts with teh fairy-san's and about the fairy-san's interaction with everything else. So far we learned nearly nothing at the very beginning, but gradually we learned about their ability to do absolutely anything as long as it's fun or joyous, "Watashi" and other humans have no names for a reason as well, they are all observers of the events that happen, after all, mankind has declined, and the next season, mankind still declines, so this story is not about humans at all.
I was kind of hoping to see "Watashi" as a much smaller person as well, maybe next season ?