Bottle-top “throw”

Last summer I spent a few days at Lake Taupo (an enormous volcanic crater-lake in the center of the North Island). Early one morning I went down to the lake’s shore to look for pumice for jewellery & sculptures. In the car park I found several bottle caps discarded by drinkers the night before, I gathered them up & threw them onto a rock by the lake’s edge & took this photo.
To me the pic says a lot about the thoughtless disposal of rubbish.