Group interview, friendly interviewers who have to obviously follow a guideline for the interview. Split into two groups: one half goes to the checkouts to observe/shadow and the other half has to do a group activity (making a paper sculpture that will stand up within a set time) and then answer standard questions. The activity itself isn't important, it is more about showing that you can communicate etc. You then swap over with the other half of the group. You also have to say when you're available- as a uni student who only wanted a summer job it is clear they wanted someone more permanent as I didn't get an offer. I personally think it is more about your availability and flexibility than the skills you show at the interview (interview is more of a hoop you just have to jump through).