Will Traveler's Painting That Reveals All

I found a copy of the painting that Will Traveler stole from the Drexler Museum. The copy I found is a giant mural on the landing between the 2nd and 3rd floors of the U.S. Capitol, and it depicts the Continental Congress at work.

The central figure (by which I mean the one in the center) in the painting is holding up 4 fingers, which must relate to the 4th Branch which seems to be the central conspiracy/mystery of the Traveller series. There likely is some historical reason for the 4 fingers,e.g. casting proxy votes for other colonial/patriot delegates to the Constitutional Convention, but that's not relevant for our purposes.

Oh, and Robert E. Lee's war horse was named Traveller. Since he was a leader of the Rebellion Against the Union, maybe this means that the 4th Branch is in rebellion against the current government.