[Though he's playing through all of it, he notices when something changes. His eyes watch it all happen as his fingers still on the instrument. When Aether starts awake, Sizhui is looking out a window to see the night sky out there. He knows only an hour of time has passed and yet the sky suggests that maybe fiver or six hours have passed instead.

That explains the lack of rest.]

In truth? I think only an hour. But I believe I have an explanation for why you are not resting well when you are having these dreams.

[He points to the window.]

What must be five or more hours have passed even though you and I only experienced one together.