Hehehe, the vote had already been cast before but I failed to leave a few words. There are not many words to waste on a great shot like this. Perfect focus, DOF, exposure and presentation. I really do love the square format. It gives it a sense of 6x6 camera work.
This is the perfect example of a single primary focal point. The instructor is where the attention goes. The secondary focus follows the arms and leads you around within the frame. There is nothing that leads you out of the frame or away from the instructor. I am also very impressed with the perfect exposure. Black and White are the two hardest tones to capture well and keep the surrounding well exposed.