Someone confesses to the speaker that they have one feature they notice first about themselves, the one they like least, and they would happily cut it away. The speaker answers quietly: they notice it first too, but they see it differently. Where the other person sees a flaw, the speaker would kiss it first. The title, "Y-Shaped Fissure," suggests a small mark or split, though the poem never says exactly where it is, and that vagueness keeps the moment private.
The speaker's feeling is tender and a little protective. The closing images, "alabaster pebbles" with a shallow basin between them, turn the feature into something smooth, pale and delicate, like a landscape seen in soft light. The "cold and hazy morning" and the "half asleep, half awake" line give the poem a hushed, drowsy mood, as if this is whispered in bed. The poem's point is gentle but clear: what we hate about ourselves may be exactly what someone else finds most beautiful.