Here are the details on the prison itself from the announcement:

The Escapists series began in 2014 as a Steam early access game before being completed a year later in 2015 and then made its way to consoles soon after, giving fans the underdog story—the one where the little indie game worked through early access, gained critical recognition, and eventually got a promising sequel—that we all love. Although the original Escapists was released without any multiplayer, the sequel not only features a versus mode, but both online and local drop-in/ drop-out co-op that allows for up to 4 players, which is an incredibly exciting improvement for any game series.

It mostly just means we sit at a virtual lunch table together. 

The game is coming to PC, PS4, Xbox One and Switch and features loads of cool stuff developed on top of the first game:

The follow-up to 2015's (or 2014's, depending on your feelings on Early Access) hit indie game will feature four player local and online co-op, giving your friends the ability to drop in and out of your latest escape attempt.  There's a new trailer out, in which you can see one of the most crucial parts of cooperative escape plans:  four-piece bands.

If you've never played the game, The Escapists is all about doing favors for your fellow prisoners, crafting gear (like pickaxes and shovels), and completing your daily duties all while trying to concoct and execute an escape plan. That same gameplay will be the main focus for The Escapists 2, but this time you'll be able to do it with up to three other players.