References to sealand
Is a hint to the future reveal of David's telepathy, insinuating how his 'dreams' which were most likely others' thoughts had differed greatly from the norm
Showcases Sophie's innocence
shows Sophie's persistence and wariness
The repetition of the 'I mustn't' is like a chant, insinuating that
Sophie was in pain yet she could still persevere it and insist on getting home through her own efforts, reinforcing her insistence / persistence / perseverance
All are deviations : if its non-human its a offence, if it is a human it is a blasphemy
It shows how the both of them had gotten close to each other during this period of time such that they were open to sharing their preferences to each other. The development of relationships from initial wariness can also be seen which later explains why the Wenders were like family to David
Development of relations [not that impt tho]