I learnt about the importance of the monitor, especially for the director who can then focus on the whole frame instead of looking through the camera lens - this also saves time and makes the filming process more efficient.
I also learnt about the importance of the different roles communicating and working together- the camera operator, lighting person, assistant director, director and the performers need to know what is going on at all times so they can adjust the set and get ready for the next shot in time. All these roles working together is very important for a successful video.
I also learnt that being the performers can be long, tiring and tedious sometimes but in the end the result can look really good.