How it works and what it is about exactly
This is a so-called thumbnail or a brief preview of the post that you see on Facebook after referring to any webpage – a picture, a caption, and a snippet of text. Sometimes, the social networks do it themselves and the result looks the way you think. More often, however, it would be more practical to customize the preview.
Basically, the social network will take the initial image of the post, the title of the post, and the first few words of the content. However, this is not sufficient for the needs of many users.
The easiest way to make changes is through the free Yoast plugin, which is key to SEO of websites built in WordPress. A very skilful, yet neglected feature of a favourite plug-in is also the adjustment of thumbnail images for individual social networks.
After installing the plug-in, the Yoast Control Panel will appear right below the editing panel when you create or change a post or page. Just click on the social networking symbol and you can easily change the caption, description and image for Facebook or Twitter.
Carefully consider the text that you put in the shared post. It does not necessarily have to coincide with the perex, but the summary of the content that lures the reader to click and read the post is important.
Why change the preview for social networks
Because sharing on Facebook or Twitter brings millions of visitors a day to WordPress sites, their importance cannot be underestimated – not even a preview of the post that rotates on the Internet.
Social networks use so-called metadata when sharing a post – caption or snippet, short text to read out the content of the post. If there is a picture, caption, and label carefully selected for sharing, the impact can be greatly increased to support website traffic.
Does your preview image not appear on Facebook?
If the link appears without a thumbnail image when being added to Facebook, do not worry. On the Facebook Open Graph Debugger page, enter your link, click on "Debug" and then "Scrape again". Facebook retrieves all the data from the page and repairs the recorded information. The next time you post, the link will show everything correctly.
The same procedure applies if you already have a social networking article and want to edit the preview image or labels for further sharing. Already shared posts will remain as they are but the rest will be displayed with new information.