What metaphors are used in Perfect Light by Ted Hughes?

Based on a 1962 photo of Plath in a field of daffodils holding their two children, "Perfect Light" describes the physical scene and ends with an ominous metaphor suggesting the mother's inescapable fate. With atypical softness and sentimentality, Hughes addresses Plath directly as the "you" in the poem, portraying her in angelic terms and comparing her innocence to that of the children, before concluding that such a blissful moment was doomed to fade into a "perfect light."