Hitchcock's Film's Revisited by Robin Wood

Madeleine is "continually associated with death" such as the portrait of Carlota, the grave, the house. She exerts a fascination of death, drawing towards oblivion, a "longing for and fear of death" which culminates in the scene among the sequoia trees. the whole sequence is bathed in an atmosphere of "romantic dream", visual beauty is intensified by the emotional overtones.
 The sequence culminates in the kiss by the sea. Hitchcock uses his audiences "escapist expectations" of wanting to see a hero they can identify with "involved in a romantic wish fulfilment: hence at the climatic moment dream romantic cliches are merged." Another significance is that if the "sequoia trees are "the oldest living things" this sea is older still."