Google updated two Search Central documentation pages, adding guidance on how publishers can tell Google which image to prefer for thumbnails in Search results and Discover. The company added a new section called “Specify a preferred image with metadata” to its Image SEO best practices page. It also updated the Discover documentation to reference the same metadata options. On its documentation updates page, Google said the changes were made “based on feedback” to clarify that it uses both schema markup and the og:image meta tag when determining image thumbnails in Google Search and Discover. The new Image SEO section explains that Google’s image preview selection is automated and draws from multiple sources on a page. The updated docs explain how publishers can influence that selection through metadata. Google listed three ways to specify a preferred image. The first uses the schema.org primaryImageOfPage property on a WebPage type.…