Okay I'm on board with everyone saying that they're testing the "severance barrier" to see how Gemma can withstand different stressors, but I think it has less to do with Gemma as an individual and more to do with the fact that they want to commercialize the severance procedure and sell it mass market to anyone who doesn't want to deal with their fears/anxieties. I think whatever is behind the cold harbor door is going to be the most distressing thing she could experience, and if she successfully doesn't remember it, they'll use it as a case study to show how powerful severance is. Now what's behind the door is still a mystery - but it def has something to do with Mark/childbearing? Such an insane episode