Chapter 18: Why does Katniss cover Rue in flowers?

As a small rebellion, Katniss decorates Rue's body with flowers (symbolize Rue) a type of funeral that is antithetical to the murderous raison d'etre of the Games, even though she knows they'll never allow that detail to be aired on TV. She touches three fingers to her lips and raises her arm to Rue's body as it is removed, using a traditional District 12 salute.