Some GUI menu backgrounds are horribly blocky/pixelated while others look fine and smooth. This is the example of the System Menu background. It looks like a horrible low res image or something went wrong with it. It's not only the system menu. It appears on other backgrounds as well. This appears on all menus on the right lower part of the screen (the golden buttons "Duty","Friends", "Travel" etc)
http://i65.tinypic.com/2wqzq87.png