Open Graph tags are what let you set the title, description or image to be used when your page is shared. JFBConnect uses our Open Graph plugins to automatically set the tags in some extensions. Unfortunately, we don't have aOpen Graph plugin for Kunena right now.
JFBConnect also lets you manually set the Open Graph tags to be used on any page with our Easy Tags. To do that, you simply add the following tag anywhere to the output of the page:
{JFBCOpenGraph title=Title for the Page}
{JFBCOpenGraph description=Description to be used on the page}
{JFBCOpenGraph image=http://site.com/link-to-image.jpg}You can add those directly in a thread or even within the Kunena template files. You can also use those tags within any Joomla article's that don't have a picture already.
a generic picture (logo) if there is no picture inside the topic.
You can set a default image to be used on any URL of your site in the Open Graph -> Configuration -> Defaults area. To add a logo or other default image, add the following to that defaults box:
image=http://site.com/default-image-to-use.jpg
I hope that helps,
Alex