https://imgur.com/a/WZOM5i1 is specifically an imgur album link, which bb code and this forum does not recognize as an image, whereas Reddit would recognize it(as an image or set of images) because it(Reddit) has kept up to date on software and has support specifically for albums. You can right click the image in the album for the context menu, and select "open image in a new tab" or "view image" or something to that manner to get a webpage that only displays the image, ending with a .png or .jpg or .gif like zenfur says. I think image uploaders to imgur also have a direct link at the top right corner of the image to copy that direct link to your clipboard.
