This is much more common in finance and legal firms, where much of the upside accrues to partners in the firm, and the junior people work long hours for much more modest compensation. But they're loaned money in order to get a jump start on the lifestyle that their more senior colleagues enjoy, putting them in hock to the firm. If they were to leave to join a startup, for example, they'd have to pay it back in a lump sum.

From the article under number 4:

"They encourage up-and-comers to spend extravagantly; they extend lines of credit to their rising stars. You need a big house with a jumbo mortgage; you cannot pull up to a business meeting in anything less than the best luxury car. It is part of their corporate culture."