"Generate image for social networks"
is a setting which enables generating preview with the post subject and author's username for the posts you share in social networks
such as Facebook, Twitter, and VKontakte. This preview can also contain an image from the post, if the image is larger than 600x315 pixels.
If there are no images in the entry or their size is less than 600x315 pixels, the preview will contain the post subject only.
The preview of LiveJournal post in other social networks is generated if the post was created or edited by the user of account with Professional
or Permanent package of service after 24th October 2016.
To enable preview generating, please visit the Account settings page
and ensure that the checkbox "Generate image for social networks"