Featured image (SEO)
The featured image is the primary image associated with an article or page, displayed in social media previews (Open Graph), Google Images results, and sometimes in article rich snippets. Its markup determines what Google and social platforms show when the page is shared.
In practice
The recommended dimensions for Open Graph are 1200 × 630 px. The og:image attribute must point to an absolute, stable URL — a CDN change without a redirect breaks previews on all existing shares. For SEO, the image should be named and alt-tagged descriptively, and included in the Article schema under the image property to be eligible for Top Stories.