Grrr - this is the exact equivalent of the 'smiley face' home stereo graphic that everyone was doing in the 80s. Basically it boosts 100Hz ('high bass') and 8kHz ('low treble') - meaning that you get a mix that is more flattering to cheaper mid-heavy systems and small laptop speakers.

Why does this make me so maaaad?!!! Well, because mixing and mastering engineers spend their entire professional lives devoted to making final recordings sound as beautiful as possible on a 'flat' stereo system, and are paid megabucks for this talent, then we consumers come along and mess it all up with brutal domestic graphic EQs.

The reason this setting is perceptually pleasing BTW is partly that the boosted frequencies are more easily heard on cheap speakers, and secondly that it makes everything louder (note that everything is boosted - nothing is cut). This increase in loudness is perceived by our brains as 'more' (='better').