Jessea L. Vaughan's poem is one long question, and it never stops to answer. The speaker wants to know what love actually is: where it comes from, where it goes, what it's made of, and why we hand it to some people and not others. The sentence even loops back on itself, since "What is this thing / We call love?" appears at the start and again at the end, so the poem finishes right where it began.
The one moment that hints at an answer is the middle, where love seems to disappear when "we / Put ourselves on pedestals and / Tear each other down." That suggests the speaker sees pride and cruelty as things that drive love away, though the poem doesn't say so outright. The mood is curious, a little weary, and honestly puzzled. The speaker doesn't sound angry or bitter. They sound like someone who has loved and been hurt, and who wants to understand it, even if the question can't be settled. The short lines and plain words make it feel like thinking out loud.