Echo from beginning to end. "Le Ballon Rouge" floated aimlessly in the sky for a long time at first, and the white butterfly followed "Le Ballon Rouge" all the way. The end can echo the beginning, and the butterfly flies to the sky with the Red Balloon. "Red Balloon" says, don't follow me, if you go up, there will be no oxygen, while White Butterfly says, I want to be with you forever.