The tie wire has been crimped around the insulator and has the ends bent up ready to have the line wire dropped on to it for wrapping, which never happened. Part of the pin was in the pin hole of this dug insulator, but not enough to tell if it was a straight pin or a bracket. The rear skirt is broken out and has been gone for a long time. The following is speculation; the lineman has just placed a tie wire around the insulator and is ready to attach the line wire. He is hanging on with one hand by the insulator (they didn't wear safety belts in those days). The pin breaks off and the insulator with unwrapped tie wire attached falls to the ground and has the skirt broken off. The line man breathes a sigh of relief after another close shave and a fresh insulator gets tossed up to him. Your speculation may vary.