Owen's chilling contrast between "Treading blood" and "lungs that had loved laughter" echoes a regular theme in his works, that the men who gave themselves for the war had once been amiable and friendly people before the dead "ravished" their minds.
In Owen's writing, the contrast between "Treading blood" and "lungs that had loved laughter" highlights a recurring theme: those who fought in the war were once jovial individuals before being psychologically scarred by the conflict.