In your reference list, cite an image the same way you would cite a website.
Author(s). Title of specific item cited (or, if unavailable, give the name of the organization responsible for the site). Name of Web Site. URL. Publication date. Updated date. Accessed date.
TIP! If you do not know the author of an image, start with the title of the image. If the image does not have a title, provide a brief description of the image.
Example:
Protocol Snow. Harvard Medical School classroom. Flickr. https://flic.kr/p/6wAnUu. Published June 15, 2009. Accessed July 23, 2020.