The identical mate can arise when the knight lands on e7, as pictured here. Again, the important thing to see is the number of ways the knight can get there: from f5 (again), from d5, or a little less commonly from g6 or c6 or even c8—all the squares that are spotted (and we also have put a spot on g4, since it allows Nh6# as shown a moment ago). A knight sitting on any of those spotted squares has the potential to mate in one move if the bishop’s side of Morphy’s mate is in place. Its actual ability to mate naturally will depend on whether and how well those squares are protected, etc.