Its a piece of nylon rope tied to the pole. The paper negative loses fine detail so you can't see the individula strands at the ends, so it is impossible to identify it. I hadn't realized that until you mentioned it.
The tone is actually added later by a colorizing cad program. But actually this whole scene is kind of a gray anyway because of the time of year. What the paper actually does is to record (my term) gross details like old 1930 era home cameras did. Going back to that is pretty hard now. Most of my glass have pretty good, so it is necessary to do something like paper to get that, not soft look, but lack of detail look.
It the difference between cutting a piece of cloth with good scissors, or an axe. A modern film or digital camera being the scissors of course.