The discussion centers around identifying an image that was initially thought to be a nebula but is confirmed to be a photo of a retina taken with a fundus camera. Participants note the presence of the optic nerve at the center and eyelash shadows in the lower right corner. There is curiosity about a formation in the bottom left, with suggestions ranging from it being related to pigmentation around the iris to potential signs of disease. One contributor shares their experience maintaining fundus cameras, noting that their images typically had an orange hue due to filters used for detecting macular degeneration. Overall, the consensus is that the image is indeed a retinal photograph, with various interpretations of the unusual formations present.