Hmm. Theme.
On the surface it's obvious (to those with an imagination) that the people on the seat ride are heading to the afterlife having been deceased for whatever reason. They are split into groups. Some got to go in the large tower with the elevator inside which the viewer assumes goes to heaven.
The others are stuck in their crates.
At first one assumes that these ones are going to hell, but there is a distinct lack of pain, or regret. Only silence and people whispering amongst themselves. No emotion.
I believe that place the ones in the crates went to to be purgatory.
The reason they are there isn't known, except for the old man. When the lights go on in the room, the flashback shows his death, which one assumes was suicide. People don't just unintentionally fall off bridges after all.
I think the theme has to do with how in many religious scriptures it is said that those who kill themselves are stuck in limbo or purgatory. A quiet place between heaven and hell where there is nothing.
They are stuck there, only with their own thoughts. The old man is left with memories of his life and his death when he gave up.
Am I anywhere near correct on what you were trying to convey here or am an idiot and way way off?
also, good cartoon, very stylized, you always make good stuff etc etc blah.