What is warren brown’s purpose for writing this section of the biography? Compare brown’s purpose with Powell’s possible purpose for writing his memoir “It Worked for Me”

What is the tone of the following passage from a river runs through it by norman maclean? “this was the last fish we were ever to see paul catch. my father and i talked about this moment several times later, and whatever our other feelings, we always felt it fitting that, when we saw him catch his last fish, we never saw the fish but only the artistry of the fisherman.”