Practice here is similar to what Jun described. You never ask the instructor a question during technique demonstration, much less ask Sensei. And, as Jun mentioned, if the instructor observes poor technique, he will frequently stop us to demonstrate again with more emphasis on certain points that are lacking. This is in addition to the normal observation and individual commentary...
I just started studying iaido, and the environment there is even more formal. Without sounding too pompous, I think my ability to observe technique and translate that into movement is slowly increasing.