It is ... well ... strange.
The series comprised 12 15-16 minute eps of completely computer generated graphics. Essentially these three female chibi magic-wielding fairies (complete with little wings) sorta "shoot the breeze" and do things together in some sort of alternate dimension. They periodically go to a little pool near their home tree and look in on short "clips" of alternate dimensions too.
I wish I could describe it better ... but the humor is completely off-the-wall of impossible to predict at times. I guess it reminds me a little of when Robin Williams voiced the genie in the old Aladdin Disney movie. (Williams' voice was perfect, because of the genie's magic abilities you literally had no idea what was going to happen from one minute to the next.)
Gdgd Fairies has the same element of having no idea what is coming next because of the magic abilities the fairies possess combined with that Japanese surrealness and
in their comedy.
Hmm ... it really best speaks for itself in some ways. If you can survive through 1 or 2 of the eps I am positive you will get what I am failing so badly at trying to describe here.
Now I happen to like this kind of humor when it is not too, too offensive in "crossing the line", and for me Gdgd Fairies stays within boundaries. But I can't guess what other people's reactions might be. Really ... the wildest parts of bizarre humor from Nichijou is the only recent comparison I can think of ... hmm ... or maybe Dororon Enma-kun Meramera a teensy bit?