thumbnail-design A design-craft skill — write the promise, design the concept + text, produce the brief , and plan the A/B test . The agent designs + briefs + plans ; a human or image tool makes the raster ; the YouTube thumbnail is uploaded + tested natively (no WoopSocial field). The POV: a promise, not a poster — designed as a unit with the title A thumbnail drives 70–80% of click decisions , and the viewer decides in under a second — so its job is the click that leads to a watch. Two rules anchor everything: the thumbnail + title are one unit (the thumbnail shows , the title tells — they…