Arlene & Terry are dressed up like zombies, because they are totally plugged into the zeitgeist. Whatever was trendy five years ago, they are on it. They are both ridiculously cute at this time, as is Sookie:
Sookie: "Oh, it's Halloween today?"
Arlene & Terry: "Zombies are the new vampires! In terms of pop culture and not our society on this show, where vampires are real and thus wouldn't hold the place in pop culture that they do in the real world. Like that!"
Sookie: "I don't know about zombies, but your severed toe necklace is super cute."
Oddly, it is.
Sookie: "Arlene just told me that your brother died. I would have come to the funeral."
Sam: "I kind of just want to forget the whole thing happened. Why haven't you been at work?"
Sookie: "Because you fired me?"
Sam: "It's like the Gift of the Magi. What a comedy of errors. Anyway, you can have your job back. Lafayette called in sick with hooker bitch ghost disease, Arlene's fucking useless and Holly's got that face of hers, so we're in need of some extra hands. For work today I will wear a flattering Civil War cap that makes me look like a train conductor on a children's show, and you will wear these bunny ears."
Sookie: "Our relationship is pretty adorable when this show remembers it exists."
Marnie: "Since I've got you tied to that chair, I can subject you to an entire long lecture about how Halloween is the Witches' New Year. I will say Samhain wrong, like everybody else on this show throughout the episode, and also pretend that Wicca wasn't invented fifty years ago."
Jesus: "I will lose consciousness while you go on and on about this irrelevant subject."
Marnie: "There's possibly an interesting worldbuilding thing in this scene about how our cultural understanding of witches as hags in cloaks on brooms was actually engineered by the vampires for political reasons? Maybe. Maybe that's what I'm talking about."