Can effortlessly understand practically everything which he/she reads or hears. Can summarize information from various written and spoken sources, logically recounting the reasons and explanations. Can express him/herself spontaneously with high fluency and precision and also make finer nuances of meaning clear in more complex topics.

By passing this exam C2 you demonstrate you can, for example: 

understand everything in German that you read and hear effortlessly 

summarize information presented to you from a variety of sources, written and spoken, and, in doing so, synthesize correlating arguments as well as explanations 

organically express yourself in a fluent and precise manner and articulate the finer nuances of complex arguments.