[She notices when he trails off, hears the hum of approval and takes it as permission to keep running her hands over his back, giving him something of a backrub/massage as he stood there.]

Schrodinger's wings? I guess that's a somewhat apt analogy. They're there, but they're not there, but they're both until one or the other is proven, but that can't be done without opening the angel from the box, right?