At times it would be nice if struggling teachers could watch how someone else would handle a group of students (possibly a class with several special needs for differentiation or behavior modifications) because hearing how it could be done is not always very effective. There are times when it would be most effective and efficient to simply see how a master teacher could orchestrate the same class.
If the master teacher could go into the class for a few days as a substitute, video could capture classroom management techniques and learning routines being implemented. This could result in meaningful dialogue as previously recorded segments of the struggling teacher could be compared with video of the same class with the master teacher.
I was blessed my first three years in the classroom with a colleague, Nikki Galantis, in the classroom next door. She was a 30-year veteran teacher who had that "you-will-behave-well,-and-I-know-that-you can-do-this-work look." She taught me how to manage any class with "the look" and encouragement. I was able to see her step into my class during brief moments when I had to speak with a parent or give input in a meeting/phone conference. It was eye opening to see the students respond to her commanding yet caring presence. I may have mastered her techniques quicker if I had been able to capture and study both of our interactions with the same class via video analysis.