At this point in time, images can only be added/changed to custom social media posts created on the Communications tab.
Adding an Image to a Social Media Post
1.) Navigate to the “CALENDAR” tab in the main menu.
2.) Click on the arrow icon on the social media post you wish to edit.
3.) Hit "Choose File"
4.) Select the image file you'd like to upload.
NOTE: Twitter image files must be less than 3.14 MB
5.) Hit "Upload"
6.) Hit "Save" when you are satisfied with your changes, and you're done!