I actually don't know what MMD is - although, looking back there were a few Gardevoir pics I've uploaded here that seemed to use this same lovely 3D model (looks like it's from X and Y!).
Anyone who's both bothering to look through this collection and familiar with MMD probably already has this, I bet, but if not you should totally take a looksie at Supurreme's deviation page via the link to the right! The actual picture, cute as it is, is most likely just a demonstration.