Speaker or Narrator, and Point of View
The exact identity of the speaker isn't clear, but he's contemplative and curious.
Form and Meter
Seven verses of six lines, iambic tetrameter
Metaphors and Similes
Metaphors:
"Washing at their identity" The people visiting the effigy don't literally wash away the couple's identity, but they help erode it by disregarding the couple's identities.
"Their final blazon" The couple's intertwined hands serve as a metaphorical blazon, or description of a coat of arms, providing the key to remembering them.
Alliteration and Assonance
Alliteration:
"supine stationary voyage," "soon succeeding eyes," "helpless in the hollow," "smoke in slow suspended skeins"
Irony
The couple's intertwined hands, perhaps just an afterthought by the sculptor, have come to represent eternal love even though the couple likely didn't marry for love.
Genre
Poetry
Setting
A chapel
Tone
Contemplative, serious, curious
Protagonist and Antagonist
Major Conflict
Whether or not love can survive past death.
Climax
"Time has transfigured them into/Untruth."
Foreshadowing
Understatement
Allusions
Metonymy and Synecdoche
Personification
"Light/Each summer thronged the glass," "A bright/Litter of birdcalls strewed"