Your rating in Runway Challenges depends on how other players like your look, and how well they think you’ve dressed up for the theme at hand. If you get a rating you’re not satisfied with, you can always play the challenge again and try with a different look. You can also make sure to max your Trending bonus by wearing clothing with the Trending label over the thumbnail and to max your Unworn bonus by wearing clothes you haven’t worn before, which is going to boost your rating.