Currently when adding a new Image Gallery to a StoryMap, the only way to add an image to the gallery is to "Upload" one. However, after an Image Gallery is created in a StoryMap, then there are additional options for how to add photos, including "Link" and "This story". Please allow these additional options to be present initially when first adding a new Image Gallery to a StoryMap. (I often want the "This story" option when adding a new Image Gallery to a StoryMap, but all I can do is "Upload".)