Light conversation asking if you're flexible. No real assessment. If you work in retail before then you will have a much better chance of being hired. I wouldn't say you need to worry too much about the interview.
J'ai postulé en ligne. Le processus a pris 1 semaine. J'ai passé un entretien chez Shell (Leeds, England) en janv. 2016
Entretien
Submitted CV online and had an interview within a few days in the office at the petrol station. Standard questions asked about experience and your strengths/weaknesses. Nothing tricky involved. Whole process was completed within a week.