Spoiled Rich has just been elected head of the Ponyville school board. With this new job, she's moving back to Ponyville full time, creating a situation where the hired help is too busy with the move to adequately serve her daughter, Diamond Tiara.
Enter Spike, number one assistant to a Princess and hero of the Crystal Empire. He can handle a pushy little entitled filly like her, right? Right??
This story is a pseudo-prequel to Crusaders of the Lost Mark. It sheds some light on why Diamond Tiara had a change of heart, which in my opinion, was way too abrupt in the episode. This story takes place around the time of Princess Spike, even though it bears nothing in common with that episode's premise, other than featuring Spike.