To do this, you must first upload the image(s) to the “Files” TAB of the device card. You can then mark up to two images with an asterisk. The tagged images will be displayed on the device card home page.
Once you’ve marked two pictures, the blank asterisks disappear. In order to replace an image, you must first uncheck one of the images (click on the asterisk) and then you can make a new selection.