You may want to add a table of contents to your Lightbox or Project to provide more information and context to users. You can select a poster image, add a description and provide contact emails. We recommend adding a table of contents to Lightboxes you will be sharing, or collaborative Projects.
Once you’ve enabled the Table of Contents, follow these steps to add a Poster Image to your Lightbox.
To add a poster image just copy and paste the desired image’s GUID (Globally Unique Identifier) into the poster image field in the Manage action menu.

Tip: The poster image in a Table of Contents view is responsive to screen size. This means it will re-crop as you change to different size screens. We suggest you choose files that have a strong visual interest in the center of the frame, so that it looks good on multiple devices. Long horizontals, like panoramas, will frequently work best.