cipher - There is a secret message in the picture #2

There is a secret message in the picture, can you find it?

This solution is also a clue (how to solve) to the previous one - There is a secret message in the picture.

This picture was neither used in the book nor it is a part of the 50 trillion dollars challenge so I hope it does not violate any rules.

Answer

Looks like the answer is:

MUKO

Because

There are rocks in the art that indicate morse code, with the square rocks being dashes and the skinny rectangle rocks being dots.

Translating from morse code,

- -   = M

. . - = U
- . - = K
- - - = O

We get the word MUKO. I don't know what a "MUKO" is but that's the only answer I see. :)