Talk:Hearthbreakers/@comment-25410106-20151020225001/@comment-10390252-20151021180832

Random OMG possibility: That isn't Princess Twilight; it's Sci-Twi.

That said, it's much more likely to be an animation error or a 'deliberate mistake' because it's the imaginings of someone who doesn't know that Pinkie's friend Twilight is the Twilight Sparkle.