Metadata is information that describes a page on your Refined site, but is not actually visible on the page itself. It lets you control the preview text and image that show up when you post a link on another platform, for example on Twitter, Facebook or Slack. Modules such as the Pages module and the News module also use metadata to show a preview text or image. If a page has no metadata, the link’s preview text and image are taken from the on-page content.
...
To add metadata to a page, go to the top-right corner and click the … three dot Three dots button.
...
Guidelines for feature image
In the Pages module, the cards are displayed in 4:3 portrait (vertical) format. In the News module, they are displayed in 4:3 landscape (horizontal) format. While it is possible to upload an image in a different ratio, keep in mind that the module will crop it to fit the 4:3 format.
...