Images in Link Shares - Sharing - Documentation - Facebook for Developers
Describes how to specify image(s) in link shares, how to ensure they are displayed properly, how to update them and some caveats. (should be 40-180 characters, 150 recommended)
Describes how to specify image(s) in link shares, how to ensure they are displayed ... first time, the Facebook crawler will scrape and cache the metadata from the URL shared. ... This can also be used to update the image for a piece of content.