He is a master of "fishing for fish, not for fame". His leisure is a deliberate protest against the noise of worldly ambition.
If you were to look at a scroll of 瀑树钓叟 , you would likely see:
What is the meaning behind a painting of a fisherman? - Facebook
Delicate ink washes representing the spray of the waterfall or the morning mist, which creates a sense of mystery and "emptiness".