I think what it tells employers, who don't know better, is that the person is a Certified Information Systems Security Professional, and they might have heard all government security employees must have one, so it must mean that the people are extremely skilled. In this, I'm not qualified to say but my hunch is, not very likely based on a few untechnical people I know in the last few years who passed the test successfully.

What it should tell employers however is that the person is capable of critical thought and has a light familiarity with a wide range of security concepts.