Karyn wrote down on the brochure: Jon has blond hair.
She looked up and saw that Jon didn't have blond hair. Apparently, the bracelet only worked with what she says, and not with what she writes. That's good, because Karyn usually keeps a diary and she didn't want to have some her writings come true, as some of them were a bit exaggerated. Also, some of her English classes wouldn't be affected, with all of the essays and such that she would have to write over the next week.
Plus, this was a safe way to communicate with others. There's no chance of changing something.
She looked back down at the brochure and erased the sentence that she wrote.
She looked up at Jon and said "I think this is a good way to talk with each other."
"If you said it, then it's the truth," Jon said jokingly. The fact was, though, it wasn't really a joke at all.