Short answer:
Most non-charge pump Fuzz Faces connect the positive rail to both signal ground (input and output jacks) and circuit ground (everything between the input and output caps, while using the negative rail as the circuit supply.
The layout you refer to connects the positive rail to circuit ground, but connects the negative rail to signal ground. This is possible because the input and output caps block DC.
The downside is that
sometimes this method oscillates uncontrollably and no amount of tinkering can make it work.
This all makes more sense if you look at the schematics instead of the layouts. Which leads us to...
Long answer:
Read
this page.
Then read
this page.