Have you ever been to the US? (Serious question). If you have and you're out shopping, there's a very different attitude they have when it comes to shopping, and I've seen it across several states and all kinds of stores.
Straight away the sales associates come over to you, ask you if you need anything, generally compliment what you're buying, suggest other additions. Essentially, they're trying to make you come off as helpful as possible to the consumer, while selling as much as you can for the company. No matter what happens, it's all about the customer. The shop can visually be quite messy, but you still have to greet people when they come in and be very smiley, and just overall very "american", if you'll forgive me using that as a stereotype.
Generally speaking in Britain and Europe, they'll wait until you approach them for help, they won't be as pushy or as bubbly or enthusiastic. Working in Victorias Secret, I'd imagine it would be expected of you to say things like: "Wow, that's a great bra you picked. One of the girls tried it on the other day and it's a really great fit! Would you like me to get you the matching briefs? We have two different styles and they're actually on promotion for 5 pairs for £20 at the minute!" (all of that pushed in between 'normal' conversation with the customer, directions to the fitting room/cash desk, etc, see how great I am at impromptu selling, hahaha!)
Just so you know I'm not totally sprouting a load of crap - I work in a store that ALSO pushes 'American style' customer service, as they call it. It's usually the likes of big American companies that are only breaking into Europe now, think Forever 21, Abercrombie and Fitch, Victoria's Secret, Hollister,.... if you've never been to a place like that, the closest I can think of it is how they act at some make up counters like MAC. I hope this helps some of you guys because trust me, it's what they'll be expecting and looking for when they're hiring staff.