Just for future people wanting to know they started with a styling exercise where they give you a scenario of a customer and you have to go and find some outfits that you would take the customer to the fitting rooms with and then explain your choices. Then the manager picked out a top and asked how I would sell it to her.
Then in the formal interview bit it was the usual questions like why do you want to work for Phase Eight, how could you be an asset to the company, why do you want to work in fashion retail, asking about your experience and then a lot of questions where they give you a scenario and ask what you would do, such as how you'd handle a return and what you'd do if there was still things to do but your shift was over etc.
Hope that helps!