It's the moment life lost meaning. The survivor can't go back to the happy life of the past because it never existed. The reconciled future is only play-acting.
Like the song she sings says, "we're late, darling, we're late... everything ends too soon, too soon".
I loved this movie.
Very ambitious, but overlong and not as deep as it considers itself to be. Is it just me or 140 minutes is way too much for what this film wanted to say? Also, couldn't they devote some of that time to character development?