This was trippy, and anon was a troll for making them say their greeting every time they hear it in order to stay alive. Then again, it was most likely a dream.
It took me a while to get it- But it's not a dream; It's a premonition. The *real* pain is about to start, and being forewarned isn't going to help them. (The sleeping Reimu is in the exact same position as before it explodes.)