Simile in The Odyssey
It's unclear whether Athena transfigures herself into a bird or merely makes use of her enchanted sandals to fly off into the air. If indeed it is the former, this fits into a larger theme of gods disguising themselves as animals. Perhaps the most famous example of this might be Zeus turning himself into a swan while pursuing Leda, one of his consorts.
Homer makes an interesting choice here by describing an island as a shield. This simile could foreshadow future difficulties Odysseus might face when trying to get to land.
Virility is one of the prized Greek virtues, and this powerful simile expresses the raw masculinity that Odysseus represents in the eyes of Nausicaa. Since we know that Nausicaa is looking for an appropriate suitor, this would be a very attractive quality in a mate.
Homer illustrates how much Nausicaa outshines the others by likening her to Artemis, the goddess of virginity, childbirth, and the hunt, in an extended simile.
Homer continually creates space between the Cyclops and the men to justify Odysseus’s actions. This simile further dehumanizes the Cyclops, as if the men are not killing a living creature, but simply dismantling an inanimate object.
The use of this simile helps give the reader a better understanding of the men's reaction to seeing Odysseus. After the Cyclops, the Laestrygonians, and the enchantment of Circe, Odysseus' men certainly have reason to celebrate in such an unrestrained fashion.
Odysseus is purposefully testing Penelope's loyalty by telling her these stories. The long simile in this sentence not only indicates the grief and care that she still has for her husband but also satisfies Odysseus.