nnnnNNN recording on a rooftop on a windy day suddenly makes your voice and instrumentals more clear than it would in a studio.
Sis her voice is the exact same clarity when she's talking as when she's singing. The only difference is the other guy's mic is on, a standard microphone without wind protecting foam, which is causing wind noise during the speaking bits, and the piano drowns it out otherwise.
Plus she cuts the phrase short at 2:31 and swallows, and you can faintly hear it on the mic. Plus the laugh at the end.