When a post a link of a post to facebook, it doesn't show any picture, just the title and the link. Until recently, it always showed the featured image and if that was not present, the blog header, next to the link. I am using Weaver II 2.0.
If I post a link from another wordpress blog on my facebook, it still shows a picture next to it.
My blog: http://www.musicaljournaal.nl