Rice is a staple amongst many people in Sumatra, including the Lembak. The Lembak are particularly known for owning the majority of the ricefields in Bengkulu.
Rice takes a few months until it is ready for harvest. It turns from a bright green to a light yellow. It is then harvested, husked, and dried out in the sun. After the rice has been dried, it is "aired out" or "threshed" as seen here. She is virtually shaking out all the extra stuff that might have been in the rice (the husks, little pebbles, etc) to clean it. This falls to the ground while the good rice stays in the basket. Soon after it's prepared and ready to cook and enjoy!