One of the lesser-known improvements (to me, anyway) that WordPress.com implemented at the end of November 2012 was the ability to manage Discussion Settings on images, in addition to Posts and Pages. As a result, you now can allow or disallow comments and pingbacks on images almost as easily as “Likes” and Shares”.
Comments are enabled by default on your site globally (under Settings>Discussion Settings>”Default article settings”), meaning that commenting is available on Posts, Pages and images, whether in Attachment pages or in the Photo Carousel. And, of course, if you’ve disabled commenting globally on your site in the same Discussion settings, then commenting will be disabled on images as well.
Thanks to the Discussion module, which has been available for a long time on the Post Editor or Page Editor screens, as well as newly available in the Edit Image screen, you can fine tune even further where visitors can leave comments.
Enabling or disabling commenting on individual images can be managed either in the Media Manager screen or from the Media Library. If you are in the Media Manager, click the “Edit Image” link or from the Media Library, click the “Edit” link. Remember to click the “Refresh” link or the “Update” button if you make changes.
If you don’t see the “Discussion” module in the Edit Image screen, click the “Screen Options” tab in the upper right corner of the Edit Image screen and check the box next to “Discussion” and the module should appear.
Another subtle but very welcome improvement. Kudos!