It's a Windows Media Player video. Yes, I unfortunately have that on my Mac. :(

A woman sits on a subway across the aisle from a man. She starts imitating his motions: crossing his legs, slouching and spreading his legs, leaning sideways - and other people on the subway are watching by now - leaning forward on his arms, jumping up on the seat, runing his arms down the sides of his body - and then he pulls off his shirt! Others on the subway crane their necks to see her reaction as she smirks and shrinks back in her seat.

I didn't catch what it's an ad for.