Thank you for reaching out to us. I can definitely understand how important it is for your image to post along with your email to appear on Facebook. I have a couple of questions in regards to this issue, as I would like to thoroughly investigate this situation.
1 - Would you be able to provide a screen-grab of the Social Share post and your Facebook post?
2 - What is the Campaign name that you are attempting to post?
3 - If you happen to have the post, would you be able to provide the URL for that post?
4 - For verification, did the image not post at all or did it post with an incorrect image?
You can email us this information to social_support(at)constantcontact(dot)com along with a reference to this post and any additional information that might assist us with locating the issue.