In Roald Dahl's "The Twits," the author explores the idea that a person's inner thoughts significantly impact their outer appearance. If someone constantly harbors negative or ugly thoughts, these feelings manifest physically, resulting in a face that becomes increasingly unattractive over time. This contrast highlights that persistent negativity can warp a person's appearance to the point where they become almost unbearable to look at.

On the other hand, Dahl emphasizes that individuals with good, positive thoughts radiate beauty, regardless of their physical traits. Even if someone possesses imperfections, their inner goodness and kind thoughts can shine through, making them appear lovely and attractive. Thus, the narrative suggests that true beauty stems from a person's character and mindset rather than conventional physical features.