<head> section, which sets a
cookie with a random value on each reload. This time the value is:
Furthermore, there's one CSS and one image embedded into this page. Both of them should receive the cookie value. However, not any browser does set the cookie fast enough, or at least not in a reliable fashion, which is a known problem ("race condition"; you might read here or here for further information).
These are the results for your current browser (I encourage you to try this also with other clients, and be sure to hit reload a few times in order to spot if it's consistent or not!):
Congratulations! As for the CSS request, your browser did set the cookie fast enough!
Sorry, this was not fast enough! The CSS request didn't carry the correct cookie value ...