Out of decorum, he does not bring that can to the podium. He opens it in the ante-room just prior to entering the room
It goes like this:
POTUS: Let me open this and make the announcement. ‘PhISSSSSSSSH”
Then: “Ladies and Gentlemen, the President of the United States”
Dubke seen at presser. Been appointed a position. Karl rove back in WH through him.