It's a reference to the special clothing that you must wear inside a chip plant. The spacesuit-like uniforms are normally white, and they evidently reminded someone of rabbits, and the garb came to be called "bunny suits."
I confess that I could never quite see this, either (no fur, ears or tail, for one thing), but I guess I simply lack the necessary imagination.
And the advert makes it even tougher to figure out, by using a blue-colored suit.