Final answer:
The boy with Sergio thought it was weird that the girl had a scarf on her head because it was unusual for a child to have long hair and wear a scarf.
Step-by-step explanation:
The boy with Sergio found it weird that the girl had a scarf on her head because it was unusual for a child to have long hair and wear a scarf.
In the given examples, the boy commented on the girl having long hair, the black scarf holding something important, and the woman's dress looking like a purple black.
These instances highlight the unusual and unexpected nature of the scarf in relation to the characters and their appearances.