If you want to get a visual impression of the Congress atmosphere, take a look at last year’s photo documentation. There will be a Photo Documentation this year as well. Moreover, there is a Flickr interest group named 22c3 where participants can put their pictures. Tag them with something like 22c3 chaoscommunicationcongress ccc and use a copyleft license (e.g. Creative Commons 2.0 by).
Hackers are very sensitive about a possible appearance in photos, especially if these photos are widely spread on the internet (which is generally the case nowadays). So please make sure to ask people before you take their picture. When people don’t want you to take a photo, please stop using your camera immediately! It goes without saying that it is generally a bad idea to take photos at the Hack Center!