The trailer for the movie has her say something about lunch, turns into a werewolf and kills some guy. Since Pip has seen this movie and says nothing like this happens I guess this scene was made to make the trailers more 'exciting.' In other news the trailer for the next Harry Potter movie involves Harry becoming a drunk
The entire point of her character is that she doesn't go out of control like that and, if she ever did, the Watch (specifically Carrot) would stop her by any means possible. In the trailer you can even clearly see someone else in the Watch right behind her!
"Wait, Angua, you're gonna kill that guy?"
"No, just trying to appeal to a general audience."