The question was posed to me recently that if Diana was given the gift of beauty from Aphrodite at birth, then how and when did this manifest itself.  Of course this hinges on the not-yet established assumption that Diana still got blessings from the goddesses upon her birth which has not been defined one way or another yet, although the revelation that Zeus is her father might change that (though both can still fit within the origin easily enough.)  The Perez origin, most of which has to be a little changed now, described how the souls of the Amazons came from those of women who had met their deaths at the hands of violent or vengeful men.  Only one such woman at the time was pregnant, and these two souls met in the Cavern of Souls, where they waited for rebirth.  As the unborn infant was not yet ready to be born anew (actually born for the first time) the other Amazons were freed while Diana’s soul waited.  When it was deemed that the time was right the soul was released into its mortal form.  As it was being released though it gained its blessings.  Some of these blessings dealt with physical abilities such as strength and speed, while others dealt with mental abilities such as a hunter’s mind or wisdom.  Of course these are attributes which are a combination of both nurture and nature – even if you are born smart or physical capable you still need to work at these things in order to hone them – but beauty on the other hand is not really something which requires much other than what nature gave us at birth.  This is not true of course, there are environmental factors which can lead someone to be less attractive, as well as subsequent physical damage, but generally speaking the genes we are born with result in our appearance.  There are of course some complications with that, as our attractiveness changes over time based on what processes our bodies are undergoing.  For instance, someone might not be considered attractive at 13 but then will be at 18.  Underlying this all as well is that beauty is in the eye of the beholder.  To go back to her birth though, it should be noted then that her beauty likely took affect right away, thus in essence Diana has never really seen her true face (which to be fair is she looked like her mother would not be that unattractive either) but the presence of the one blessing altered her perception forever.