Katniss’s initial reaction to Peeta’s interview involves Peeta being violently shoved into “an ugly urn filled with fake flowers.” The fact that the urn smashes gives an indication of the violence with which she pushed him.
Her fury relates to the fact that Peeta relays to Caesar Flickerman that he has long held feelings for her. She does not initially understand that the move was a strategic one on Peeta’s part, designed to encourage the audience to become attached to them and therefore inclined to support them with gifts once they arrive in the arena. In Katniss’s view, his declaration of feelings for her make her look weak, although Haymitch is quick to point out, while reprimanding her for assaulting Peeta, that “he made [her] look desirable.”
Peeta’s plan had the desired effect. While Katniss had reacted with fury, the rest of the audience reacted with sympathy and began to see the pair as “star-crossed lovers.” Katniss does not initially get the significance of this. Her big concern is being portrayed as weak, and Haymitch has to explain that being portrayed as a “heartbreaker” can only help her to get sponsors. It is only once Cinna tells Katniss that Haymitch is right that she calms down, and she later apologizes to Peeta.
Peeta makes a point of using his pre–Hunger Games interviews to drop bombshells relating to him and Katniss. In his interview in the following book, just before entering the Quarter Quell, he tells Caesar that he and Katniss are already married and that Katniss is pregnant. These rumors, while utterly untrue, have the same effect of getting the audience eating out of Peeta’s hand in support of the duo from District Twelve.