No, the diagram is incorrect.

The point rails form the frog, along with the wing rails. Today most prototype frogs are a one piece casting, so they don't really use the point and wing rails to form them.

Direction of travel is determined by the switch rails, often incorrectly called point rails because they are often referred to as "points", as one end is pointed like a blade.

There are many misleadingly labelled diagrams out there which only serve to confuse, because they take a mix and match approach to their terminology. 

Even NMRA documents mention switch rails and the frog point rails. Their diagram in NMRA Technical Note TN-12 doesn't match the one you found.