I understand the logic behind comments in Activity stream page you are talking about, so I tried to enable comments in all buddypress pages, just I was not able to do it. I thought if I upload a photo directly from the Activity page then maybe I have to enable comments in /members/username/mediapress/wall-photo-gallery and in all the /wall-photo-gallery/subdirectories. I tried adding a snippet in functions.php of my child theme but it didn’t work. Both Enable Commenting on single media and on single Gallery in Mediapress settings are active (I think this settings are not related to my issue, just for telling you my setup). I tried commenting photo_upload activities using buddypress Comment button in Activity page on your demo site too, the result is the same as on my site: comments made via buddypress Comment button don’t show up on any mediapress components. By the way I got this same issue even if I upload photos from /members/username/mediapress/wall-photo-gallery/manage/add/ page, so I really don’t know what I’m missing. Thank you as always for your help Brajesh.