The article’ s featured image is not displayed in Facebook posting.
When you share a post on Facebook, or when Jetpack Publicize publishes a post to your Facebook page, Facebook crawls the page and looks for Open Graph meta tags in the head to build a complete post preview (with an image, title, description, …).
Jetpack automatically creates these Open Graph Meta tags for you unless you already use another Open Graph plugin, in which case we let the other plugin handle things. Looking at your site, it seems that the Yoast SEO plugin is in control of the tags, and the look of your posts on Facebook.
You can see what Facebook sees by entering one of your posts’ URLs in Facebook Debugger:
https://developers.facebook.com/tools/debug
That Debugger can help you understand why Facebook didn’t select a Featured Image for a specific post.
Also, I would like the article text content to not be displayed.
To remove that excerpt, you can create a custom Publicize message thanks to the Publicize box appearing on the right side of the editor, right above the Publish button.
