Here is a possible plan for the question "How does the poet show the contrasting tones and moods in this poem?":
Setting - Island vs London
Imagery - Sea vs Motorway
Language - Descriptive vs Muffled
Emotion - Content vs Weary
Rhythm - Flowing vs Choppy
I could write PEARL paragraphs comparing the setting, imagery, language, emotion and rhythm in the two sections of the poem.