Anxiety is shown to be a nervous emotion with some luggage to get off (and that’s no figure-of-speech, because she was carrying some suitcases when she meets the emotions). She's extremely anxious about meeting preexisting emotions like Joy, especially because she wants to make a good first impression. She is also an extreme planner. Everything must go exactly as it must happen as she had planned, with every mistake being seen as something that may "haunt" her later.