The poet subverts common light and dark metaphors and instead uses summer as a metaphor for her grief and depression at the passing of time, and by implication the loss of loved ones
Capitalised nouns, describing abstract concepts like Grace, Quietness and Grief
Cosmic elements — Summer, Dusk, Morning etc — are also capitalised, and represent the passing of time and of life, and the changing moods, including grief and depression experienced by the speaker