Yes, it's body language, and some plays, it looks like he simply loafs. He jogs out the route sometimes if he thinks the play is not coming his way, and it would cost Dak who would sometime force the ball into Coop, who looked like he didn't even want to be bothered. Not a good look.
I'm kind of done with Coop, to be honest. Yes, he has his moments, but I'd gladly trade him for some young talent (draft pick) or for some defensive studs.
Having said that, some teams do fear his ability, so teams plan around how to stop him, even though he's rarely a deep threat. So he DOES help keep teams honest. Thus, I'm a little torn...but I'd definitely privately ask around to see if any FO loves him enough to offer something of value back (high draft picks or defensive stalwarts).
At this point, when the lights shine bright, in tense games in December, I just don't trust that he'll show up...because some games he totally goes missing.