Very informal. Ask some behavioral questions and prior sales experience. They also seem to look for cultural fit in terms of having an energetic personality, loving tea (though some of my colleagues hated tea and only drank coffee...), and if you're willing to sell a lot. To be honest, the interviews are so subjective, you'll probably get the job easily if you're likable and seem well put together. The main thing the store manager is concerned about is hiring someone who can sell tea and make goal. Of course, likable people who appear smart will have higher probability of doing so.