That's a beautiful story often used to illustrate the true meaning of peace.
The tale you're referencing is about a king who promised a great reward to the artist who could paint the truest picture of Peace.
Many skilled artists brought forward magnificent paintings.
However, the winning painting was brought forward by a young artist and was unlike the others.
The artist had painted a scene that initially seemed chaotic:
The king declared this painting the winner because he understood the artist's message:
Peace is not the absence of trouble, but the presence of serenity within the turmoil.
It is easy to be peaceful when everything is going well (like the still lake), but true peace is the strength to remain calm and centered even when life's difficulties (the waterfall) are raging all around you.