Yet again another beautiful piece. The human anatomy and perspective is beautiful ( just cant do people inside perspective like that) Shadowing is perfect. I challenge you (only if you want to) to put faces hair and clothes onto the people. I think it would be a fun challenge ^-^
The only actual string you see is the knot around the pencil, all the rest is drawn on paper. So the top right one is just a continuing piece of thinly cut paper. At least that's how I think he did it, I could definitely be wrong though.