What is the dramatic significance of the painting Isle of the Dead in The Ghost Sonata?

The Island of the Dead, a painting by Arnold Bocklin, is used at the very end of the play. The imagery creates the idea that death has come and there is nothing left, as it has isolated the family as well as the Student from the world of the living. The stage direction reads, "Bocklin's picture The Island of the Dead is seen in the distance, and from the island comes music, soft, sweet, and melancholy." The painting itself depicts a rocky island, with a grove of trees on it, like something out of a myth. It has the uncanny, beautiful, and haunting qualities of Strindberg's ghostly play.