For many years search engine results have shown various images size publicly made available by site owners. Last year (September 2019), some extra controls over the content preview was introduced to Google Search followed by Bing who announced similar capabilities for their Search Engine earlier this year (April 2020).
In practice, this means that many sites do not get the benefit of large image previews, and may be losing out on traffic. Today, WordPress sites do not opt-in to large image previews by default even when “Search Engine Visibility” setting is turned on.
Below is an example comparison of