In Roald Dahl's book "Matilda," the character Fiona is compared to an iceberg, highlighting her striking outward appearance. This analogy suggests that while Fiona might attract attention for her beauty, she lacks depth and substance. The comparison indicates that her allure is superficial, concealing an absence of meaningful qualities beneath her exterior.

This portrayal serves to emphasize the significance of inner strength and character, as opposed to mere physical attractiveness. Fiona's character might echo a broader theme in Dahl's work, where appearances can be deceiving, and true value lies in one's personality and intellect rather than superficial traits.