What is hard to understand about it? Most link sharing happens on facebook. If you share a link in facebook, people will click on it, IF there is a picture that interests them. If there is no picture 99% of people will ignore the shared link. So for the author of this website it would make sense to add any picture at all. When someone shares the link to his website, FB will automatically find the picture. But there is none.
What's hard to understand about it is that it's a mishmash of words thrown together with no coherency. Your point about having an image to make Facebook sharing makes sense, but there's no way to extract that point from your original post.
There is a dot missing between "sharing" and "Facebook". I just see that now. If there are more grammar issues, I am always open to learn. It's not my mothertounge, though. And I think I have that attribute in common with a lot of readers here...
