For those who have missed Jimmy's guessy guessy boxy boxy series - he invites celebrities (who have something to promote, usually a film) to guess what's in his mystery box, and vice versa. He's been doing it for quite a while, and it's beginning to show. Look at how genuinely excited he was the time Jennifer Lawrence was on.
Now he's breaking out lispy "British" accents to pass the time while reading the intro, before wildly overcompensating with some floor fisting (seriously) at the end of the video. Emma Stone, however, keeps up her end of the bargain with more than her fair share of unbridled wide eyed moments. What a pro.