In a comment, it's the same as reddit (i.e.,  markdown). As a link post to an image, there's no upload support or rendering support in SN for that (yet). So the workaround is to do a Description post and then do the markdown for the image in that.
Support for media uploads has been discussed, and there's an issue on this in SN's Github repo.
markdown). As a link post to an image, there's no upload support or rendering support in SN for that (yet). So the workaround is to do a Description post and then do the markdown for the image in that.