These two phrases mean similar things and are used to emphasize that Edom will lose its important status. (See: [[rc://en/ta/man/jit/figs-parallelism]])
Something that is insignificant is spoken of as if it is of small size, and can easily be overlooked. Alternate translation: "I will make you insignificant among the nations" (See: [[rc://en/ta/man/jit/figs-metaphor]])