What is the metaphor in the poem Three Lunulae Truro Museum by Penelope Shuttle?

It's written from the perspective of a visitor to the museum. He views the lunulae and imagines their history. The clock ticks. He gets some suspicious looks, and has to leave as they are closing. His partner, or friend bus him a postcard, and they step outside where there are autumn leaves.

Themes of identity, time, cyclic movement.

Arguable the narrator is a women, proof being it's written in a gentle sensitive, delicate way. It's said "only an old woman would notice its weight" suggesting is one.

The reference to "freeze" in stanza 5 and "winter" links to a seasonal reacurrance, spring representing young people and the narrator at the end saying "enter the thin gold remains of autumn" so she is nearly at winter, which is old age and eventually death.

In the beginning there are euphonious sounds (soft, gentle sounds) such as "moon" "women" "mood" "winter" etc.

Lots of delicate, fragile immagery, linking to nature such as the simile about insects legs, "sickle shapes", "fragment of a lip, eyebrow fine as a spider's threat", "thin gold remains of autumn"

The reference to insects legs is an extremly odd simile to chose to use, and since insects legs are extremely quiet, we can't hear them, suggests time is unseen, quiet, goes on unspoken and unnoticed until it's winter and you're old.

There's much more analysis too.