Originally posted by Metallus
It's just a secret joke, put in by nerdy programmers so that nerdy fans can uncover them years later .
Nerdy? Hmmm, I'm not quite sure how I feel about that.
Glottis' doghouse was the very first background in the game. It's placeholder art, aka "programmer art" meant to indicate very clearly that art is missing where it was expected... Testers knew to look for it and report it as a missing-art bug.
As someone else mentioned, if you see it, you probably somehow got into an overhead camera mode. Congratulations, you found a bug! During development, we used top-down shots to help lay out walkable areas. However, those shots aren't useful in the finished game so they were taken out when we needed to fit the game onto the CDs.
GF Lead Programmer
Doghouse Artist Extraordinaire