Self promotion here, our BuddyBoss theme includes Photo uploading to profiles and groups out of the box (mobile too):
http://www.buddyboss.com/demo/members/guest/pictures/
Photo Uploading
You would need to set up some other system for voting up the photos though. BuddyBoss also comes with a system to “Like” content, and shows who liked it. You could change “Like” to “Up Vote” or whatever and then create a custom built section showing the most liked activity posts, limiting it to the ones with photos uploaded. You’d need to edit some code for that.
