Ayman,
JFBConnect will try to automatically detect the first image on a page, but we can't detect videos currently.
The way to call out that video would be to add the following tags:
{SCOpenGraph video=http://domain.com/link-to-video}
{SCOpenGraph video:width=400}
{SCOpenGraph video:height=400}
{SCOpenGraph image=http://domain.com/link-for-image.jpg}Then, re-run your page through the Open Graph Debug tool and the proper tags should be found.
I hope that helps, but if you have other questions, just let me know.
Thanks,
Alex