It literally sounds like Ariana's version but far away so that all that straining fools you into think it's Katy, so your ass doesn't look stupid straining to hear something we already have.
Maybe the demo was, but the final definitely wasn't. It's too hard to tell with Jeff coughing up a storm. Still, knowing he's UMG distribution, I doubt he'd have a demo.
She's had too many, I'm sure she wouldn't mind. 
