Background Pony #DAFA
There definitely IS a connection with Twilight Sparkle. I am now watching the last episode of S9, and many of the decorations in the concert hall are very similar to those in the throne room in the Canterlot royal palace. Twilight uses the eight-pointed star as her magical symbol, so it’s not out of place.
At 00.00.14 one sees a glass window showing a mysterious tree under the moon, the sun - and something unidentified? Maybe the Wishing Tree?
It is very possible that the lone unicorn in front of the Wishing Tree in the first page of the book (38.40) is Flurry Heart, although her fur is somewhat whiter, and she may have been the one who confronted Opaline in the next page. As the book may have been made in the first generation after Equestria’s collapse, it is possible that the authors knew very little about them, including that they are alicorns.
Some of the magic that the Bridlewood unicorns use is very reminiscent of what these crystal ponies did, and since it is possible that there was Flurry and Opaline in the book, there is a possible connection with the Crystal Empire. Maybe Flurry was with the Mane 6 to stop Opaline, and we don’t know what kind of cutie mark she has, but if this is based on ice… a sibling conflict?
There were three central unicorns in front of the Wishing Tree in the cover. And if there is a connection between the Crystal Empire and Bridlewood, it could be Cadence, Flurry - and Opaline in those twenty years between the last two episodes of S9.
In the side showing the ice against the fire, it is possible to see the shadow of a tree and a moat bridge as the one unicorn with the same fur color that Opaline is standing on - possibly where the dark castle is located. It could be where Flurry confronted Opaline before the Mane 6 came in and defeated her, taking her magic in the process. Then they put Opaline in chains under house arrest, which we still see signs of on her.
The last page of the book then suggests that this happened many centuries before, as there was a happy ending to the tales. Zipp assumed that the conflict led to the loss of magic. But I think it was the conflict that led to the creation of the Unity Crystals.