The information that is automatically pulled in when you post a link to your content on social media is the meta information.
As you see below when I go to post a link to my piece of content an image and text is automatically associated with that link.
This information is used by social networks and search engines and you can customize what the information says when you navigate to the Configure section of the content builder.
The image that is pulled in is either the image you are using on your cover page, or your background image depending on what you have added to your piece of content and you cannot change that, but you can customize the title and the description.
To change the title click on the appropriate title field and enter in the text that you would like to display as shown above.
To change the description click on the appropriate description field and enter in the text that you would like to display as shown above.
Once you have made your changes scroll to the bottom of the page and click save.
Your meta information is now updated as you can see in the image below.