You can add multiple social preview images to your responsive pages for users to choose from when they are posting a link to your page from various social sharing websites. For example, on Facebook your site's social preview will show the images you've setup, alongside a headline and caption for the respective page.
To add social preview images
Select Settings on the Left Sidebar within the responsive editor.
Under Site Settings, go to Social Preview.
Select add image.
Select an image from the file manager (my files).
(Optional) Delete an existing image from the social preview by select the 'x' icon.
Tip: Be sure to test what your social preview images will look like on social media by copy and pasting your website's URL into a Facebook post after you've added your social preview images. This was you can see what your visitors will see when they share links to your site from their Facebook profile.