The scene where Mikasa pretended to give the bread to Sasha but then just ate it in front of her was hilarious. Even the quiet, stoic types can be trolls. Well, it's also possible that Mikasa wasn't trolling and just felt pissy because Eren bailed while she was speaking from her heart.
But even that scene paled in comparison to her epic introduction. The confused look on the drill sergeant's face as he tried to figure just how stupid she was... priceless.