What does "stepping over the necks of peasants" mean here?

While a Chinese friend of mine was reading the story, The Standard of Living by Dorothy Parker, she came across this sentence:

Annabel and Midge passed without the condescension of hurrying their pace; they held their heads higher and set their feet with exquisite precision, as if they stepped over the necks of peasants.

My friend asked me if “stepping over the necks of peasants” was some sort of idiom. I am not a native English speaker. And I couldn’t find such a phrase in any dictionary. I assume this is just a simile, but I failed to see the exact meaning behind this description. So could you please help analyze the phrase?

Solution 1:

A more common phrase than to step over someone's neck is to have one's foot upon someone's neck

have one’s foot on [someone’s] neck To be in a superior, dominating position; to have someone at one’s mercy; to have complete control over another person. This expression owes its origin to the following Biblical passage: Come near, put your feet upon the necks of these kings … for thus shall the Lord do to all your enemies against whom ye fight. (Joshua 10:24-25)

So the phrase is indicating that the girls are walking as if they are of superior status. Later in the story, when they have priced the necklace they leave the shop as though they were going to a tumbrel. This is a reference to the vehicle that was used to transport French aristocrats to the guillotine during the Revolution. So over the arc of the story the image of the girls' pretended status alters.

Solution 2:

After a little search, the expression does not seem so idiomatic. However, remember that the girls wear high heels, and act as if there were rich (and they are not).

This sentence is successful in conveying several strong images at the same time:

• they walk with a lot of ease, like being from the gentry, being able to "step over" with heels,
• they pretend they stand above the vulgar crowd,
• they act as if they were uncaring of the surrounding, such as folks belonging to lower classes.