If you have a skincare/cosmetic store background, you'll do fine. Most of the interview questions consists of your basic retail "what would you do"s and "has there ever been a time"s. Remember, the customer is ALWAYS right!
Now skincare...as long as you show genuine interest in your our hygiene, skincare, ingredients, and their sustainability, (and show your support for "no testing on animals!" cus theyre that kind of company. First and first most, its always good to read up on their best sellers if you dont normally use loccitane products (I happen to LOVE loccitane, so it was fairly natural for me to talk about products), JUST in case.