I wouldn't put all my faith in somebody holding a piece of paper in front of a camera. It has been faked before. There are two instances I'm aware of. One time it was a photoshop job by an account of a fake girl​ posting naked pics. And the other situation (it happened before my arrival on Steemit but I read about it) was ​a guy paying a pretty girl on the net in exchange for a picture of her with a Steem logo & date so that he could pretend to be her.