There are lots of ways to teach your dog to step in the contact zone. This woman has set up a ramp for her dog, and is clicking every time the dog's foot touches the contact zone that she has marked off. She is probably giving the dog his reward off-camera.
Don't forget: you always need to give a reward every time you click! Can you set up a little ramp for your dog in the yard? Tell us how it goes in the comment section!