[FOSDEM] Improve main picture on website for use in social media

[Pander]

Hi all,

Could the website offer a nice main image for usage in social media? If
you share a link to http://fosdem.org/2016 on Twitter, LinkedIn,
Facebook, Google+ and so on, the map of the campus is being shown as
image, which is not the most representable image for the event.

It is possible to indicate in the website (hidden or not) which
picture/logo should be picked up by social media when sharing the link
of the site. Could someone have a go at improving this?

Thanks,

Pander