What strikes me with this video is the style of commentary.
This level of detail and style reminds me of a very 'British-style' Oxford-Cambridge boat race!
This is very interesting and I would love to see some of the instructionals and books I have been exposed to over the year try this style. It is so detail rich. For Tai Chi this is a god-send, I suspect as the movement is so intricate each detail counts to some amount, I think, (I do not do Tai Chi but this is my instinct).
The heel-toe shape is something I have been told about and it makes me empathise with this video.
I like the camera angle, too. It captures the posture and the lighting is very good. I would like to see stripes on the sides of the track suit bottoms / shirt to show skeletal alinement more maybe ?!