Celebrities, they're just like us! 

Okay, Fallon is sort of scraping the bottom of the barrel with this gag with Katie Holmes. It's basically what everyone does with their iPad/iPhone/miscellaneous Apple device when they first get one, but purportedly funnier because this is Katie Holmes and she's so straight laced?

Or maybe Holmes just wasn't up for the usual madcap stuff that Fallon usually gets his guests into (doing tumbles, playing beer pong, flip cup and other frat games etc) and this was a last minute thing. Either way, we do have to give them props for turning it into a competitive game, which is now something that you can play to kill time on long journeys or just in general.

Via YouTube