Yes, using phase cancellation it cuts the mids while effectively boosting the upper mids and highs. The low knob does the same thing in the other direction. This type of thing was originally used to restore tired old tape recordings that had gotten dull sounding. Once people by and large stopped using tape, they started marketing it as a magic box that makes everything better.
If you have something that is just really dull sounding, for whatever reason, this box might be able to make it useable. But it is really easy to go overboard with it because your ears get used to the sound very quickly and suddenly, everything that isn't that bright sounds dull to you...so you start adding it to everything, and you end uo with a mix that can peal the paint off the walls.