Pigtails on adult women?
How do you define pigtails? That varies based on region.
Pigtails, to me, are braids that start as ponytails. Ponytails are bunches of hair tied with an elastic, tie, or ribbon. Does this even matter?
The effect is cutesy. It takes more effort to take someone seriously when they are in pigtails...probably a cultural bias because they are associated with little girls. Otherwise, I mostly don't care how people dress themselves up.