Its the classic 'pretty woman' moment isn't it - they treat you better because they think that you have money if you have a Hermes and they want some of it!
I walked into Hermes in Bal Harbour with my toile/berenia Trim and all the SAs ignored me...go figure that? I wish I had brought my Kelly or Birkin to see then how they would treat me.
i think everyone judges you by your appearance, SAs are just no exception. it reveals more about the person doing the judging then about the person being judged, ironically.
It's typical that SAs often look at the way you dress. One way to demand attention is to wear a very expensive watch or a Chanel tweed jacket. They mean super-money.
*Want VIP treatment? Park your sports car outside the store. Don't have a sports car? Rent a Bentley with a driver.* (Just kidding of course..)
Whenever I go high-scale shopping, I just put on a dress wrapped with LV shawl with ballerina flats (*it's so comfortable!!*) and wear my black-diamond Alain Silberstein. You don't even need to carry a birkin, they will look at you immediately.
I don't think this really happen in other upscale boutiques like LV, Chanel, etc. If you carry a birkin to these stores, they will treat you like a queen. Maybe for Hermes, is that SAs have seen countless of customers coming in with their birkins so it is a normal sight for them.