Wild Heart - dressing room demo

[UndoingTheLaces]

That version of Wild Heart where she's singing in the dressing room to the instrumental demo of Book Of Love. Does anyone know the story behind that? My copy is really bad but when the music starts up it sounds like she says "this is the one I was telling you about... this kills me". They seem to be having so much fun with it. Like Lindsay interrupted her singing with his song so she decided to say to hell with it and make his song hers. LOL!