During an interview you may experience lots of interruptions and oddities. A good interviewer will try and stop a lot of this but you might still be disrupted.
This disruption could be people entering and leaving the room, conversations happening between people not directly interviewing, people stood behind you, people taking notes or any number of other distractions.
If you find it very distracting, like someone stood behind you, then I would suggest asking for it to change. I was once being interviewed by four people and a further two people sat behind me making notes. It was really uncomfortable. I didn’t really understand what was happening so I asked for clarification and change. They wouldn’t. I made my excuses and left.
Sometimes distractions are just careless planning and fidgety people, this can be excused. Sometimes though it could be institutional, like I the example above. I realised with the interviewers lack of flexibility and change to HR corporate rules that this was not a company I wanted to work for.
Sometimes you might not have the option of walking out, but I would always suggest you raise your concerns.
Most of the time the interviewers simply don’t realise they are making candidates uncomfortable.