The contrast between the World of the Living and the World of the Dead is a rather clever play on class distinctions in the Victorian era. On at least one occasion, the two realms are literally identified as "upstairs" and "downstairs". The World of the Dead, as a reflection of working class society, is colorful, lively, and lacking in social restraint. Even Emily, who was wealthy in life, behaves more like a working class girl, being vivacious and free-spirited (in contrast to Victoria, who is proper and demure). By contrast, the World of the Living is drab, stuffy, and restrained — very much like the upper class.
To take the class analogy a bit further, consider that Victor, as one of the nouveau riche, would literally be caught between the two worlds: the Van Dorts have risen above the working class, but are not yet recognized or respected as members of upper crust society (as indicated in the first half of "According To Plan").
Bonejangles and his musicians perform jazz-style music... which is another product of working class society!
After Emily transforms into a cloud of moths, moving on at last, it leaves you wondering "Why doesn't that happen to everyone? Are they stuck in that nightmarish town of the dead forever?"
Alternately, it leaves you wondering: "Wait — did Emily actually go somewhere — or did she just disappear into NOTHING?"
She reached nirvana, obviously. It's very Buddhist. She learns to let go of her desires and attains freedom and peace.
According to IMDB, the filmmakers wanted to imply that her spirit moved on to Heaven, but went with the generic symbol of the butterfly to avoid tying it to any one religion.
So what haunts the other dead people? What keeps them stuck in the town? Why cannot they go to heaven? A lot of people seem to have a lot of issues.
Endless torture for Barkis Bittern
The Fate Worse Than Death regarding Barkis Bittern, who after unwittingly consuming poison, is now one of the dead, which conveniently removes the restriction that the dead cannot harm the living, and has an angry mob descend upon him. Made worse in that we never really do find out what they do to him. Nothing Is Scarier.
Double on the horror when you realize that, no matter what they do to him, he's already dead. That means that it's very likely never going to stop.
Nah, after a few centuries of Cold-Blooded Torture, it's highly likely that the other dead would find other things to do.
It gets even worse when you consider what possible reason Barkis could have for coming back for Victoria after finding out her family was broke. He was probably going to murder her. After doing something else... He does declare that she's still his wife, and therefore his. Just for added Evulz, try and guess which he will do first....and how often.
Two of the residents of the world of the dead are young children.
It's Victorian England. Kids died a lot back then, due to such things as accidents like falling out a window, being run over by horses and diseases for which there was no proper cure or the cure was too expensive.
As sad as it is, children do die.
Bonejangle's song explains to Victor the story of the Corpse Bride. She eloped with a man she though was in love with her and wanted to marry her. "And he killed her." Not only that, but remember: "[He] told not a soul, kept the whole thing tight." Considering that her creep of a fiancÚ is still alive and fairly young by the looks of it, there may still be Emily's mourning parents out there, terrified out of their wits and wishing their daughter would just come home. Or write them a single note, letting them know that she's all right.