England and the Caribbean are constantly opposed in Wide Sargasso Sea, but what's more important is to think of England and the Caribbean are ideas, products of the imagination. England is just as much an exotic fiction to Antoinette and Christophine as the Caribbean is to Rochester. By exoticizing England in this way, the novel is overturning a long tradition of looking at non-European countries as other, alien, uncivilized – and thus ripe for colonial conquest, as seen in Rochester's constant attempt to get at the "secret" of the locale. Instead of being a far-off, foreign locale, the Caribbean becomes a place that reflects back on the characters' own notions of Englishness – you could say that one set of islands is a reflection of the other.
Antoinette's experience of homelessness in both England and the Caribbean indicates how she is doubly at a disadvantage in both societies as a Creole and as a woman.
By reducing England to a cardboard box and accentuating the brilliant natural landscape of the Caribbean, Rhys overturns an English literary tradition of viewing the Caribbean as an exotic world home to everything foreign and hostile to English civilization, and indeed, to civilization in general.