Epic similes are long comparisons used to make the poet's meaning vivid. Odysseus returning home to rout the suitors is compared to a lion finding fawns in his den and attacking them. Some of these epic similes are set pieces that give the poet a breather. Irony heightens the drama of the story. The audience often knows Odysseus is actually present, but the characters do not.
Repetition is part of oral tradition.
The ears lose anything spoken only once, so the poet repeats. So when a character talks, his or her words come through Homer and the conversation tends to be in long, rather formal speeches rather than quick dialogue. The poet-narrator's eyes see past and present as equally interesting and valuable.