Well, these pages are normally reliable when it comes to not posting fan-made fakes and passing them off to everybody else as the real thing. Usually if they post fan art they describe it as such so as to not lead readers down the path of thinking its something official from Paramount and the franchise.
Suffice it to say, no site or page no matter how well intentioned or how good its track record of avoiding complete B.S. is bulletproof. They got fooled just like some of us did. It happens.