Unknown icon displayed in the image field


I am using an upload function in my site. When someone uploads the image, it will appear in 2 places on the site. When I test, the image appears in one place but not in the other. When I look at the collection, I see the image is placed in the image field where it needs to be but there is also a small icon of an oval circle with a dash in the middle at the bottom left corner. Does anybody know what that icon means. I have attached a screenshot.