How are the exercises in the runner’s warm-up different from a targeted stretching exercise such as the hamstring stretch shown here?

The warm-up involved a lot of movement as I went around the cones, but the woman in the picture is sitting on the ground and not moving. Movement means that your cardio is activated. So, I’d say that the warm-up offers cardio along with stretching, while the woman in the picture is getting the benefit of stretching only.