This wallpaper shows a scene of parting and thing below the characters is the dome that's covering Tokyo in that series. The clouds that are distorted by wind symbolize the characters dramatic feelings.

I have recently watched the movie of this evangelion-esque show and while I liked the TV show very much I wasn't so fond of that movie (which recycled 90 percent of the TV animation footage).
Although that character scan was of acceptable quality I decided to fully repaint it by using my graphic tablet (thanks to chibikko for advice on the colouring). With clean vectors being very popular at the moment I wanted this wallpaper to look like being traditionally painted.