{∅, {∅}, {∅, {∅}}} : Rage Against the Meat Grinder

In prison you are observed carefully by Guards ensuring you don't do anything inappropriate. Occasionally other prisoners may tip off the Guards about your behavior.

In the office, you are observed carefully by bosses ensuring you don't do anything inappropriate. Occasionally other workers may tip off the boss about your behavior.

At work if you don't like your job, you can leave it for another job. In prison if you don't like your cell, you can misbehave and move to another cell.

A prison is a 24-hour job, you can never leave it. An office is a 5 day a week job and you have weekends off.

The exception are prisoners on periodic detention who must check in one day a week and hang around in the detention centre for a few hours. When at work, you must check in 5 days a week and hang around in the office for at least 8 hours or 40 hours and more a week. Only the most severe periodic detention would require a 40 hour week.

A prison is typically cube shaped with very small windows. An office is typically cube shaped with large windows. You cannot climb out of either type of window.
Some offices have no windows while similarly prisoners are severely reprimanded by being put in an isolation cell. An isolation cell has no windows.

Work gives you a "decent salary" which typically is just enough money to pay all your expenses such as house mortgage, food, medical expenses and entertainment, leaving you a small amount, effectively pocket money, for savings. In prison all expenses are paid and you are given pocket money each week for savings.

In an office you are restricted to your desk surrounded by wall dividers, your world is effectively an area of 9 square metres. In western prisons, human rights organisations have prevented cells being as small as 9 square meters.

In the office you are required to think about one job and only one job. You do that same job 8 hours a day, 5 days a week, around 49 weeks a year. In prison, if you decide to work (which in some prisons is a privilege), you may choose completely different types of work from time to time.

Too much thinking is not encouraged unless accompanied by constant movement such as fingers on keyboard or writing to indicate you are working productively. In prison no one measures your productivity. You only work when you want to. Assuming you aren't part of a chain gain that is.

In some cases a prisoner may be restrained to live in their house and must never leave it. This is achieved by wearing a non-removable electronic device which will warn authorities if the wearer attempts to leave the "defined area". In an office the limiting electronic device isn't nearly as complicated. Its simply a clock. It restrains the worker from leaving the office for more than an hour (lunch) between the hours of 9am to 5pm.

In an office, fellow workers constantly watch your computer screen resulting in a self policing policy. Prisoners don't have computer screens.

In prison you know you are in prison and there's no hiding it. In the office you don't know you are in a prison, and a lot of people hide the fact.