Early on in Diamond Age: A Young Lady's Illustrated Primer, the following passage is used to describe a group of people who have come to apply for jobs at Machine-Phase Systems Limited:
Hackworth excused himself through a milling group of uncertain Hindus. Their hard shoes were treacherous on the cobblestones, their chins were in the air so that their high white collars would not saw their heads off.
I don't understand the comment about the high white collars. Is the danger of the collars potentially sawing their heads off literal, or figurative? Is the high white collar something based off of real cultural fashion elements? Is it supposed to indicate some fictional device described later in Diamond Age, or elsewhere in Stephenson's works?