The ability to specify players in a game who will be able to see what you can see. I've got some friends who play warlight as well, and sometimes I want to watch one of their games. But, due to fog, I can't watch but my friend has to send me screenshots, which is really quite annoying. So you get an option "spectators" and then you can specify names, and those people will be able to watch you play and chat with you in-game. (In a special "my spectators" chatbox.)
Uservoice:
http://warlight.uservoice.com/forums/77051-warlight-features/suggestions/2370925-spectator-options-