Thanks for inquiring about posting your email campaign on Facebook. At this time, using Social Share to promote your email campaign includes a link to your email campaign. If you'd like to share your email campaign as a full image you can download it as a JPG or PNG, and then manually post it on Facebook:
Nichelle M Community & Social Media Support
Did I answer your question? If so, please mark my post as an "Accepted Solution" by clicking the Accept as Solution button in the bottom right hand corner of this post.