This image comes from official Hub media- specifically, media for My Littlest Pet Shop. It appears on the last page of the PDF. Awesome, right? We finally know that the CMC will get their cutie marks.
Not so much. I had a feeling I had seen the image before, and indeed I had. It's an image made by GlamourKat, whom you'll recognize as an animator from the show. It's from quite a while ago, though, before she got hired! Technically, then, this qualifies as fanart, though I'm sure they had her permission. False alarm, folks. Move along.