...basically comes down to collectively drinking your head off for 4 days, and having fun looking like a retard while doing that. Next to that it means the whole city turns into a big mess, which is a good thing...visually. Puke-spots around every corner, muddy confetti, and since suddenly a lot of people have these water-based spraycans there is some funny folk-graffiti as well.
Power to the people (temporarily).
I love this one, a spraypainted spraycan, minimalism in it's purest form:
I guess somebody fell asleep drunk while doing this, sums up the whole thing in one picture: