Catalog images must be at least 500x500 pixels. Anything smaller is auto-rejected by the diagnostics dashboard. TikTok Shop listings prefer 600x600 minimum.
TikTok Shop / TikTok Catalog Manager requires product images that are publicly reachable, sized within the platform's bounds, in supported formats (JPEG/PNG typically), and free of overlays, watermarks, retailer logos, or text callouts. This issue trips when one of those constraints is broken.