Maihack has always captured the classic personalities of the two heroes in these brief strips. Barbara is determined like anyone in the bat-family but maybe with a little light that is being hidden. And Supergirl is bright, sunny, and optimistic. Heck, Supergirl gave Killer Croc cookies and made him promise not to fight on Christmas in the last strip.
So in this comic Supergirl has to convince Batgirl that they should go trick-or-treating on Halloween rather than patrol. Batgirl agrees knowing that walking the streets is a patrol of sorts. They even capture the Penguin!
Far and away, my favorite panel is Supergirl mockingly saying 'Quickly Batgirl, to the candy!' with a faux seriousness on her face. Just perfect!