It's the aftermath of what could have been a cataclysmic event. The Sun, however, was defeated successful, and now slowly sinks beyond the distant skyline, never to be seen again. Moving forward, Equestria will be powered by artificial light. Surveying the aftermath, Twilight, Celestia, and Sunset have a short conversation about it.
Of course, since these ponies already know what happened, no further context is necessary.
Written for Bean's Writing Group. Art with NovelAI.