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)
The size of the image file must not exceed 8 MB. ... When content is shared for
the first time, the Facebook crawler will scrape and cache the metadata from the ...