After no longer being needed as much in the Crystal Empire, Sunburst moved to Ponyville to assist his friend Starlight Glimmer with her work at the School of Friendship. Being the new guy in town, Sunburst understood that he wasn't as familiar with Ponyville or the creatures that live there as most of the locals. Still, a couple of children running around with what is obviously a robot pretending to be a filly is a strange sight no matter where you're from.
However, when he mentioned this robot to Starlight and Rarity, they acted like they had no idea what he was talking about. Surely he wasn't the only pony in town that could tell she's a robot, right?
...Right?