The tomb was like a big box. It had two or three steps that they ascended, and they sat inside it; the front was open, but it was closed on all other sides. I'm not completely sure if the "tomb" actually did move back, or if only the front of it closing in on itself gave that illusion, but either way, it slowly closed as they sang, and the last thing you saw was the two of them kissing. Usually.
There've got to be photos....
A work of art is an invitation to love.