Link previews in other websites
You can improve the way apps and sites display your Dynamic Links by specifying social metadata when you create your Dynamic Links. This metadata is passed on to supported services in the form of social meta tags, which the services use to generate a rich presentation of the link.
For example, social apps can use the metadata to present shared Dynamic Links as cards with a title, a description of the linked content, and a preview image.
Also, the app preview page that is displayed when you open a Dynamic Link on iOS will use the metadata, if provided, to display a preview of the link's content.