There is a crow/raven next to the boy and crows/ravens are messengers of death so maybe it represents the feelings and mixed messages he got from losing someone, the raindrops could represent the depression and sadness after losing a loved one, a waning crescent could show that the boy's happiness is waning and because it's night time it shows how dark the boy has become.
The ghost girl with the umbrella could show that the memory of her is helping the boy get through this dark time.
