Not to put down Chiropractic, but they seem to utilize a wide variety of machines and tools that have little to no supporting evidence of theraputic effect. many companies who basically make the same products use marketing, not science, to suggest their product is in some way superior.
When it comes to measuring skin impedance, there are several variables that make it somewhat difficult to get reliable and accurate readings - see this paper for example. I tried to look up "scenario electrotherapy" and couldn't find anything at all, much less any technical or medical documentation. My own opinion is that this device is not likely to provide any substantial benefits over any other TENS unit and is more likely just another in a long line of marketing gimmicks.