Corporate Lockdown is a DLC for Alien: Isolation, basically 3 more maps for survivor mode where your main objective is to get the highest score by doing optional objectives and escaping the map as fast as possible. You can choose from several characters, each with different equipment. With this DLC you unlock Ransome, a Seegson executive who tries to escape the station while avoiding rogue androids and the Xenomorph.
While the idea of mini-DLCs where you play as secondary characters sounds interesting, the execution feels sadly lacking. There's no new story content, even as simple as spoken dialogue, only text descriptions at mission selection. Yes the maps are great, but you're pressed for time (if you care about the score) and the alien hunts a lot more often, making it difficult. There are no save points in the middle of the levels, so if you die you must replay the whole level.
If you enjoy Survivor Mode, then Corporate Lockdown will be more of the same, with new maps and characters. Personally, I wish these Survivor DLCs were more story-based, like for example making all optional objectives mandatory, but easier and have save points within. If you're not a fan of this mode, however, you can just skip it as it doesn't really add to the story or have specific achievements.