The quote illustrates a powerful personal experience of a migraine aura, emphasizing the intense and often disorienting nature of such episodes. The author, Hilary Mantel, conveys the profound impact of the migraine on perception, creating a stark contrast between the vibrant, but fleeting, sensation on the left side of the visual field and the complete absence of reality on that side. This vivid imagery draws the reader into the physical and psychological experience of the protagonist.

Mantel's writing often delves into the complexities of mental and physical states, and this moment captures the severity of a migraine attack. The intermittent flash of yellow serves as a poignant metaphor for how debilitating these episodes can be, as they not only affect one's sight but also alter one’s connection to the world. This passage showcases the author's skillful ability to render personal suffering into compelling narrative form.