Wrapping
Verna shook her head. 'No.' She looked up into the other's eyes. 'No, the thorn was to discover that appearance was all that ever mattered, and that what was inside' - she tapped the side of her head - 'didn't hold any meaning for him, only its wrapping.'
- Verna to Phoebe in "Blood of the Fold"
Comments
It's similar to judging people by their outer appearances rather than what's inside them.