Click the Ellipsis icon on the right side and then click the Edit link for the desired entity.
Click the Media link and scroll down to Photo Gallery.
Scroll down further and click Select Photos.
Add your image by dragging it, entering a URL, or clicking select a file to browse your computer. Note: If you would like to crop the image, click the ApplyAspect Ratio button to select a ratio.
Click the Continue button.
(Optional) Enter a Description. If the photo asset is being used for Pages, this will display as the title of the photo.
(Optional) Enter Details. If the photo asset is being used for Pages, this will be the caption for the photo.
(Optional) Add a Clickthrough URL, which is a hyperlink destination for the photo.
