Very focused, very little talking, no laughter. You're here to train. If you want to chat, find another club.
I know that many people wouldn't like it, but it suits us!
I enjoy that training to a certain extent. My teacher tried that when he first opened his dojo in the 80's. He had about six, really, really, talented students but just couldn't maintain it and was concerned the atmosphere was non-inclusive for a lot of people, thus the benefits of aikido would not be available to many...so he figured out a mid-ground approach.
I really enjoy intensive training - I think it works really well for an intensive course or class/es.
I was at a seminar with a prominent sword instructor. Very kind and experienced teacher. Someone asked him a non-martial arts related question. He kindly motioned the student to follow him off the mat. They bowed out, got off the mat and discussed the question asked, him explaining the mat was for training only, and not unrelated talk.