Yes, that’s what we are aware they are. But she’s saying “oops, it isn’t a ghost” after shooting it and finding out.
If she initially thought it was a ghost, why is she using a gun?
It’s like the theory of mind questions about moving a ball into a box when someone is out of the room.
Does she just shoot things she thinks might be ghosts to test if they are?
Is she going to murder trick or treaters when Halloween comes around?
This comic raises more questions than it answers.
No, not really. It’s not that deep:
Daphne: sees klansmen
Daphne: knows they’re racist, murderous pieces of shit
Daphne: shoots them dead
Daphne, tongue in cheek: “oops, it isn’t a ghost”
END.
That’s it, that’s literally what this is. You’re overanalyzing something very obviously intended to be anti kkk.