Actually that symbolizes that in death, Reimu is denied the afterlife and is fed to the monsters of the Sanzu.
Ah, you're right. I didn't think on that cause I always associated that with the snakes eating those souls. That, and I'm just used to Reimu having to solve everything ;)
Reimu gets a shitty job, shitty duty and shitty death. Being an impartial arbiter and not allowed to make comparisons from yokai she hunts, nor humans who are supposed to offer her patronage, well. Shafted bad. Poor woman.