General Information:

Yahweh continues to describe the Chaldean soldiers.

So they mock kings, and rulers are only a mockery for them

These two phrases mean basically the same thing. The word "mockery" can be translated with a verbal phrase. AT: "So they mock kings, and rulers are only something for them to mock" or "So all they do is mock kings and rulers" (See: rc://en/ta/man/translate/figs-parallelism and rc://en/ta/man/translate/figs-abstractnouns)