It's one of those public service ads he does sometimes.
So before Priyanka did a 12-character role in a film, Shah Rukh has already done a 12-character role in an ad. Or technically speaking, 3 ads. Still.. seeing them one after another is a bit disconcerting. I think ads is where he can act any way he pleases, while for films.. there're a lot of things for him to consider before he takes a role. However, I do agree with a commenter in a youtube post that Shah Rukh acts in films where if it hadn't been him acting in them, they would have flopped.
Take Dil To Pagal Hai, for example. What is the story about? It doesn't have a strong plot. And the way the story unfolds, there's no up or down moments and the climax.. does it even have a climax? So why do we love it so much? It's coz Shah Rukh's in it..ha! No surprise there. Is he trying to prove something to himself or is it becoz he doesn't have a nose for good scripts?? Sometimes I worry about his method of choosing movies ^^;; ..but hey, it's worked out for him so far!
Enjoy the ad~~