We're launching a web application (html/js/css, all browsers) where a user can build their own custom image as part of the experience. We generate it server side and return it to the page. It's stored in our file system in a publicly accessible location.
I can successfully use FB UI to open the share dialog, allowing the user to share caption/link and a thumbnail of the image they've generated.
If you paste a link directly to a media (img/vid) on facebook itself, it shows the image preview below the post, rather than the thumbnail that FB UI shows. We'd like to mimic the large preview behavior.
Is there a way to get the larger image via FB UI?
I've tried passing in the direct link to the image file (jpg) as each parameter in the feed and share function, and it always just shows it in the thumbnail (or no image, if I remove the picture parameter.)
Has anyone done this successfully, or have any other ideas?
Thanks