“Code Geass S1-Ep.12-"The Messenger from Kyoto"-Eng Sub”
Shirley is flustered about the relationship between Lelouch and Kallen. She gathers up her courage to ask Lelouch out on a date.
During that time, Kyoto, the organization who controls the terrorists behind the scenes, was requesting to meet the Black Knights in person.
I think Nina was just turning the pages in the book, but like a lot of animes, it seems to suggest something else. Its pretty much a way to tease the viewers.