$20 per employee per day doesn't seem like such a huge expense, especially compared with salary and office space. If it makes employees happy to stay at the office longer, it's not a bad plan.
> Consistently high-quality food, available that conveniently, is a primal attraction.
It also ensures that the employees won't leave the office premises for the lunch break. That could be a good thing (for the employer) or a bad thing (for some of the employees).