As you watch the video, note that we're anchored. By dropping anchor and fan-casting about the boat, we can work the water with a variety of speeds and depths, hang flies below indicators (bobbers), or retrieve them quickly. Because we're working shallow water, we moved in slowly and anchored as to not spook the fish we're targeting by trolling and running our boat overhead.
Because the damselfly hatch was on, fish were targeting moving flies and a faster (more moderate retrieve in reality) action had more success.