Bonta's poem circles the idea of a heart without ever settling on one. It begins with a strange image: a rose that comes to "desire its sand," as if something delicate longed for a barren, shifting ground. From there the poem keeps saying what a heart is not. It isn't the neat heart-shape of the title, and it isn't paper or lead, one too flimsy and the other too heavy. It might even be just another name for an open mouth, something hungry and exposed.
The speaker sounds uncertain and a little unsettled. Asking whether the heart can be found "from the sound of chewing" turns the search physical and almost uncomfortable, as though feeling were something you could only hear in the body's rough noises. The final lines bring in a "mad undertaker" and a blunt conclusion: "our only way is to break." The mood is dark but oddly honest, suggesting that real feeling comes only when the tidy symbol gives way.