Here it is
Bg7 makes sense of course. If white continues with 4.g3, are we heading away from Gruenfeld territory?
That would be a neo-grünfeld. I'm still new to the Grünfeld (in my holy quest to beat the annoying 1 d4 2 c4), so I never actually played a Neo-Grünfeld but it seems fairly similar to the "typical" Grünfeld: White will take on d5, black will play c5, et cetera...
As far as I know, pretty much everything with an early d5 and a kingside fianchetto is a Grünfeld. In fact I was reading a book on the Slav the other day (Glenn Flear' Starting Out book) and he even refers to a line of the Slav defence with a a kingside fianchetto as a "Grünfeld".