Ever since Diamond Tiara has changed her ways after the Cutie Mark Crusaders helped show her a better way, the former bully has been much more friendlier and more open to her classmates, rejecting her mother's beliefs towards others. In a way, she has become a totally different filly, like she was given a second life.

So when her mother, Spoiled Rich, comes back home with the news that she was denied the future position of Vice-Headmare at the School of Friendship, by the future Headmare, Starlight Glimmer, Diamond Tiara goes to have a heart to heart talk with Starlight.

(Just an idea I had that came to me, regarding A Horse Shoe-In and also justice for the fact Diamond Tiara never got a speaking role after Crusaders of the Lost Mark, but her mother did!)