What does the sentence "Mountain is man-made peak" mean?

The original sentence is taken from the couplet "Man-made peak is at the top of the mountain, and the sky is the shore at the end of the sea" presented by a friend of Zhang Daqian, a master of Chinese painting, and the artistic conception is broad and open.

"Mountain climbing" shows that a person can reach the realm of "climbing Mount Tai but being small" as long as he is willing to climb.

There is also a saying that "the mountain is the peak, the sea is the sea, and the heart is unbounded".