Your AI Cover Art Looks Great — Until It's a Thumbnail

Every card in RealFeedApp has a cover image. They aren't fetched from the articles — publishers' images come with rights I don't have — so the app uses its own bank, generated ahead of time, one pool per topic. I generated that bank once, shipped it, and this month threw all of it away and started over. Twice over, actually, because there were two separate failures and only the first one was my fault in the obvious way. Failure one: I got exactly what I asked for The original prompt asked for a dark, moody look — very dark near-black background , generous negative space . In a preview grid at full size, the results were genuinely nice. Restrained, editorial, not the usual glowing-blue-circuit-board thing. Then I looked at the actual feed. Cards render as tiles a bit under 400 pixels wide. A small object floating in a large field of black, scaled down to a tile, is a black rectangle. Not a bad image — no image at all. The model had done precisely what I asked: it put a modest subject in a lot of empty darkness. Negative space is a compositional virtue at poster size and a bug at thumbnail size. The lesson is dull and I'll probably need it again: prompt for the size the image will be seen at, not the size you review it at. I was approving art in a grid of large previews and shipping it into small tiles, and never once compared the two. The rule that replaced the old one is three words long — brighter, higher contrast, subject filling the frame edge to edge. Failure two: the model started writing the news The rewrite asked for documentary photography. The first batch came back with something I didn't expect: several images contained a coloured band along the bottom of the frame with a headline in it. Invented words, mangled letterforms, confident typography. One read TROOLDOGS NEWS . Three images out of fifteen. Not a fluke, a pattern. The cause was in the prompt, and it was three words working together. I had asked for an editorial look, described the images as news f