As parent comment said, it's part of the background. I've probably seen these bridges a hundred times, yet I don't remember the Ns.
I mean you have to willfully interprete the word "celebrating" as people dancing in the streets out of joy to read the parent's parent comment that way.
In other words: "It's in the background" rather means it's the foundation upon which (as other comments have pointed out) the French Revolution's winning side's narrative rests.