Once upon a time there was an artist girl (http://yuka-kaworu.deviantart.com/gallery/25407768). She liked to play mmorpg Allods Online and she made a short series of comic strips about her life, her friends and a gaming process. A picture from one of the strips on which she was sitting almost naked and played her game suddenly became very popular in world of warcraft community since everyone thought girl on the picture was playing wow. So, a lot of gamer girls showed up and made pictures of themselves playing videogames topless. For example, there's chinese wow forum with shitloads of photos of naked girl playing wow, you can find those here: http://nga.178.com/read.php?tid=4391737

Since there's almost no information about this artwork in the internets, some people figured out that those naked gamer girls should probably know their meme.