They're missing one tag on their pages. They need to include the og:image tag - not just for us but for any sharing. Without the tag, the "share to" platform (Facebook, Twitter, LinkedIn, etc.) won't know what to show with the story.
Here's an example: <meta property=”og:image” content=”http://www.yourdomain.com/image-name.jpg” />
Here's more background on the tag: og:image ...
This is the most interesting Open Graph tag for many marketers, because a picture always helps content stand out. This is how you ensure that a particular thumbnail will be shown when your page is shared. It can be very helpful for your conversion rates.
Make sure you set the og:image you choose, otherwise Facebook will show something stupid like an unwanted banner ad scraped from the page or nothing at all (as below). We definitely don’t want that!
It’s important to remember that if your page is static and you don’t use any sort of content management system (CMS) (e.g. WordPress), you need to change the og:image manually for each of your pages. If your website is controlled with a CMS and you installed a relevant plugin, the og:image tags are assigned automatically for each page.