Haha, good one!;)
It isn't that, though.
The way I run, APP might as well stand for Appeal. And, indeed, personality and social intelligence seem to be components in the core rules version, too. So it is not only looks. T
(I believe the characteristic was actually Charisma in the first edition, but I could be wrong on that count.)
The APP bonus represents the relatively higher social and (some aspects of) emotional intelligence/ability typical to human females. It is not simply about looks, although the greater importance placed on appearance for females of the species could be considered a factor. I don't think a long essay on evolutionary biology, reproductive fitness, advertising trends, and so on is needed here, so I won't bore you with all that. If the interpretation of APP and the modifier I use makes sense to you, cool. If not, also cool.