translation.en: Diana Reiss: You may think you're looking through a window at a dolphin spinning playfully, but what you're actually looking through is a two-way mirror at a dolphin looking at itself spinning playfully.
translation.zh: Diana Reiss： 从窗户这看过去 你可能以为是一只海豚为了找乐子，旋身打转 但其实你正透过一面双面镜 看到一只海豚 对着镜子转着玩