Every person in the crowd presses the three middle fingers of their left hand against their lips and extends them to me. It's our sign from District 12, the last good-bye I gave Rue in the arena.
If I hadn't spoken to President Snow, this gesture might move me to tears. But with his recent orders to calm the districts fresh in my ears, it fills me with dread. What will he think of this very public salute to the girl who defied the Capitol? (4.87-88)
Getting accolades isn't always a positive thing, as Katniss finds out. Here she's being saluted for her bravery and her work in the arena. But to an outside eye, like Snow's, this "salute" is seen as a threat. While Katniss didn't ask for any recognition, it makes her look like she's starting a rebellion, and the realization of this fact "fills [her] with dread."