Concept art posted by Alvaro Ramirez on ArtStation: “This was a proposal where the film would start with a narrator and the Mane Six breaking through a window and flying in the form of a rainbow.”
https://artstation.com/artwork/oArq8z
“It wouldn’t have worked for the story, but I thought it would be a treat for the pony fans to see their classic cast in CGI for the first time, before getting into the actual film.”