The answer is Personification
I think that you first write it and take it apart based by syllables, then you separate the “tricky” part (eg. most likely “gh” in “eighth”) and then you write it again. I’m just guessing though. I hope he is able to understand it.
It would help if I knew what book it was but I'm since I don't I am going to go with the fact that it is foreshadowing. Say yellow means happy as the sun well. We have the Yellow wallpaper yes. Say the yellow wallpaper starts to fade and pill that is the foreshadowing.
Using ‘SMILE’ helps
Structure
Meaning
Imagery
Language
Effect