So what would classist look like if that ad doesn't fit the description? Or does classism just not exist?
There are markers of class and money all over it, including the fact that the ad is for Harvey Nichols, one of the poshest stores in the UK. They didn't show the other women on the ad going into other expensive homes in Chelsea/Knightsbridge/Kensington, they showed them going on the Tube, walking the streets, waiting for buses - rich people don't need to do that.
That dress on the Harvey Nichols website was hideous BTW - like Granny's old curtains. The other moral of the ad seems to be don't wear clothes unless you are six feet tall, slender and beautiful. Then you can make anything look pretty.