I would say you are right BUT his other hand is the same way. If it was a signal, it would be one or the other. This looks like he's just holding it in such a way that he's going to flip it open.
Ok Anons, can we knock it the fuck off with the porn? Pornography represents everything we are fighting against. Pornography is directly related to sexual abuse and pedophilia. We need to reject pornography, and not embrace it!