this is how i would go about structuring my interview + the way i answer any questions. I dont know you so i dont mean this in a patronising way of you already do/think like this.
i got these quotes from their website:
"Their enthusiasm and professionalism will help you find everything you need to complete your perfect bathroom." Past jobs that you have had to be professional? enthusiasm to make sure the customer gets what they want, if they seem unsure offer alternatives
"Raising the Bar" aiming to approach customer understanding that some might not understand everything that they see, educating them in the benefits of spending more (something alot of places fail on as buy this its more expensive and better isnt a good explanation)
"dedicated, innovative employees to join us." They seem to want people who are going to stay the long term, turn it into a career maybe find out what you can aspire to higher in the company, store/area manager maybe?
"We need more people who relish the challenge of joining a growing business ambitious to become a major employer of the future" Again they want people with drive and they want people who enjoy the challenge
" we have recently opened a purpose-built training centre " this is where id mention the challenge bit i.e you may not know everything about bathrooms but are up for learning
"Up for the challenge?"
Maybe go into a bath store, explain what you want for your fake bath room see how they deal with you, tell them you did this when in the interview (they will be impressed) and that tell them what you liked and maybe some constructive criticism, how you would go about it? show your keen to learn and also give your ideas where you feel improvement can be applied, try and reference this to something you have done in the past in other jobs.