OSM.org does not have such a feature, but I believe you might put photos/images on flickr, or some other hosting service, and provide a public link to the image here on a note or comment.

Also, there's an app called StreetComplete, which is aimed for beginners interested in updating Openstreetmap. You can use it to apply small map changes, but it also has this useful feature: you can include photos in map notes. These photos can be viewed by others to make map changes. Pro tip: it is best to include context in photos, eg. other features that are already mapped (such as a building, or bend in a road...), so the location of the unmapped feature can be inferred.