Which is not to say that members of the team can't have privacy if they really need/want it - just that its expected that they work in a way that keeps others informed about what they're up to and how things are progressing.
Its not stressful - that is the point. Nobody has to hide anything because the expectation is that there is nothing to hide - or, if there is something you need to hide (i.e. you have self-doubt about your own competence and don't want to share that doubt with your colleagues), this is supplanted by the expectation that people will help each other if they notice a problem-solving session going on too long.
It results, thus, in less stress in the environment, more cooperation/collaboration and a more open level of communication among the team members - and we are more productive as a result of it. Also, we help each other: we don't criticise or degrade someone whose work is inaccessible.
I’d also be interested in my own reaction and whether I’d adjust to that kind of workplace.