Sized for the web, not for a gallery
Output is 16:9 and capped at 1200px wide, compressed to keep the page fast. An enormous hero image is the most common cause of a slow article page, and page speed is both a ranking input and the thing that decides whether a reader on mobile data stays.
Photographic, not template cards
Topic-relevant photographic scenes index better and look less like filler than a logo on a gradient. We learned that the hard way on another site, where a batch of generated template cards had to be regenerated as real scenes.
Check before you publish
Generated images occasionally produce malformed text or odd details. Look at what you are about to publish, and write a real alt attribute describing it.