Ahh, ok ... got it. I thought that represented the pedal enclosure, but I understand now you mean the existing electronics on the pedal's PCB.
So essentially, it's dropping the voltage from 9vdc to ~5vdc by splitting the drop between the 9vdc + and -, thereby keeping the center, well, centered. If that statement makes sense, then I guess I understand the concept here.
I'll also venture a guess that after I add a display (currently planning for a two or four character 7 segment display), I'll need to recheck the voltage due to the increased load, right?
I'll give it a go and let you know.
Thanks again!