We build the girl next to the table, mount a servo motor in her shoulder and connect a sound sensor to her.
She reacher her arm toward the table, which is detected by the IR Photoreflector in the table.
The green LED in the table will light up and the kites will start moving.
The kites always start from the middle, and when she lifts her hand over the table, the kites randomly slide either left or right on the rack, and then after a few seconds they move back to the middle.
When the kites are back in the middle, the girl pulls her arm back.