The line "The sun was shining on the sea" from "The Walrus and the Carpenter" is not a metaphor. It is a literal description of the sun and its effect on the sea.
- Simile compares two things using "like" or "as."
- Metaphor directly states that one thing is another.
- Personification attributes human qualities to non-human things.
- Hyperbole is an exaggerated statement not meant to be taken literally.
Since the line does not use any of these techniques, it is best understood as a straightforward description rather than as figurative language. Therefore, it isn't classified under simile, metaphor, personification, or hyperbole.