Why is the horse not being fly sprayed before a lesson? If they can't afford it there is something seriously wrong with the program, and they don't need to be doing lessons.
Fly bites hurt, and not fair to be riding a horse that has to put up with flies and a rider either.
It was really more about the fact that as a beginner, even benign movements feel strange and scary. Seeing the movement from the ground helped me understand mentally what she was doing. Once I saw what it was, I felt silly for feeling so unsettled about it.