Your photo shows an "R" terminal. The diagram does not have an R terminal. The photo shows a different way to wire a bypass than the diagram. The traditional R terminal is on some solenoids. We, here, don't call the side terminal on a foot start switch an R terminal.
No one asked you to explain how to wire an R terminal solenoid. That's not what the post was about. But it's good you are learning. It is one of the ways I mentioned to create a points protection resistance bypass.
Last edited by Jon G; 06/23/2023 3:31 PM. Reason: to simplify and clarify a bit