I have followed them almost all the time when they have been in the apartment and heard certain identifiable words repeated often and have seen many small things. Little by little these things are merged and for me it is now quite clear what he's doing. He may do it for a living, but the topic would be suitable, for example, the University post-graduate studies.
This thing requires a lot of concentration and research in the computer. Also relevant is that he must talk on the phone of things that he can not talk in the front of the cameras, and sometimes he takes the notebook and pen when he goes to a balcony. The apartment has visited a lot of people who are clearly not their friends, these people are related to this issue. Also, with them, he always goes to the balcony for a while to discuss. I'm not sure how she's involved, but somehow seems related.
Is it better that they would have elsewhere in the days, or days in the apartment and sometimes on the balcony? Having sex I have seen them do at least every second day, sometimes more often.