2 ideas
The more often we encounter something, the less we actually see it. Habit turns objects into labels we recognize rather than things we perceive. Imagining a newborn who has seen nothing forces the writer to describe the ordinary as if for the first time, and that reverses the numbing done by repetition.
Everyday things like teeth, which are the skeleton showing through, or a fallen apple rotting in the grass, are quiet reminders of bodies, decay and time passing. Seeing them closely reveals that the extraordinary themes of life and death are not elsewhere but embedded in the mundane. Meaning is found by looking harder at what is already present, not by seeking out exceptional experiences.