I have to admit I was at first expecting something to be diferent or out of place, like cross over characters or nudity... but seeing as how the animation seems to be all in place with Azumanga Daiohs op, it does look very good Although I dont know what the Japanese writting says, as I cant read any of it.
The author is possibly the most obsessed Azumanga fan for making this to merely re-create that intro in flash form. If I meet him/her in person we'll be best friends.
as far as i can tell it's simply a perfect flash recreation of the opening sequence and briliantly made too. This must have been a portfolio peice for a job interview and if so I hope it worked! Azumazing!