Just out of curiosity, where were you able to find that info?
Just experience. Dolby Labs has a plethora of "standards". Some are based on encoded material (AC3, DD, THD, etc.), and others (PL, DS) that simply act on a non-encoded stereo or multi-ch source.
While the decoding of encoded material provides discrete additions to the audio signal, PL and DS type processing use a number of algorithms to "simulate/synthesize" signal improvements, which many hear as coloration and would prefer to do without. It can work well on some material, but since it is guessing, it can be "not so hot" on others. The better the audio system (source to speaker), the more apparent the guessing process will be.
As to what specific algorithms are being used with the Tap is anyone's guess, but given marginal quality sources (mp3's over Bluetooth), with highly compromised amp/speakers, you can bet they involve dynamic range enhancement (envelope modification) along with EQ.
Think of it as a very sophisticated way of turning up the bass and treble controls to address a flat sounding recording. (c;