The poem is just one line, and it hits hard because of how little it says: "you had everything i'd dreamt of." The title, "kin," suggests the "you" may be family or someone felt to be close, though the poem never says so directly, so that reading is an inference.
The speaker seems to be looking at another person and seeing a life, or a set of qualities, that they once imagined for themselves. The past tense matters. "Had" and "i'd dreamt" put everything at a distance, as if the chance has passed or the person is gone. It could be admiration, envy, grief, or all three at once, and the poem doesn't choose.
The mood is quiet and wistful, with a small ache underneath. The lowercase lettering makes it feel private, like a thought the speaker isn't quite saying out loud. Because the line stops so suddenly, the reader is left sitting in the gap between what was wanted and what was real.