The above illustration is not the best to show the desired installation. It only shows a specific case (where the antenna mast ground wire comes down near an external electrical meter) and is misleading.
It doesn't show the coax going into the house which is misleading. It shows the grounding block mounted high, it should be just before the coax enters the house (this is not shown) and near the ground. I understand that this illustration may show just grounding connections but it should be labeled as such and state that it is not to scale, if you take the diagram literally and to scale you will be mislead.
the antenna mast ground should go to a ground rod in the shortest distance possible, this could be your electric service ground rod but should be separate if not close. the antenna coax should be connected to this antenna mast ground rod. if the antenna mast ground rod is separate it needs to be connected to your house electrical grounding electrode (either a grounding rod or your metal water service pipe) with 6 AWG wire (in the USA). it is important to go to that grounding electrode or the connection between your fuse/breaker box and that grounding electrode and not just any grounded wire or metal plumbing.