Karen's screensaver appears in the episode "Plankton Gets the Boot."
It has a black background with red cake mixers with white wings flying around.
Karen wants to show Plankton her screensaver, but he will not pay attention because he is working on a machine that will analyze the ingredients of what it analyzes. Plankton is sucked in, and it says he is 100% Big Jerk. The machine also analyzes her screensaver, and it says it is beautiful. Plankton ends up destroying it. Then, he says it makes her processor look fat. After that, all of the cake mixers explode in a rage. She kicks Plankton out. At the end of the episode, while Plankton kisses her, she shows the screensaver. Plankton says her processor is fat again. She then explodes in rage and starts beating up Plankton.