To adjust these Share button settings, head to Themes before selecting the pencil next to the Theme of your choice. You can find the Share button option in the left-hand-side menu.
Similarly to when you share a SmartFrame image on social media, only a small thumbnail, title and/or description will be visible in your post. The thumbnail will always be the first image in the Gallery and the title and description are automatically generated from the Gallery title and Gallery description. You can edit these in the Overview page within the Gallery.