Girls who wear heavy make up and look way different with it every day of the year should just not put on any for Halloween.
When someone asks at the party “who are you supposed to be”? and the girl can proudly/shamefully respond, “ME!”. Proud because her costume is so scary and effective. Shameful because her actual face is so ugly.
Since the make up has become part of her actual “face” that has ironically become her core identity from the perspective of other spectators, the “real face” is paradoxically rendered as a “mask”.
The reverse is also true. So either one could be a Halloween costume.