In the video, you don't see all the activity happening off-camera. Jasper, the dog, can react strongly to things that startle or overwhelm him. In this clip, I'm not talking to him because I want him to notice the things happening around us. I've noticed that when I talk to him, his focus is only on me, which for most things is great, but for a dog that can get startled by new things, I want him to look around and see the things going on around us. So, my focus is on using a clicker to mark when he's looking at things and staying calm. If he had become too excited, I would have moved away from the thing that excited him. Here, he did great. He was able to look around at all the things going on and yet stay calm and in conversation with me. It's worth noting that just before this clip, I was crouching down, giving him pets, and talking to him. Right afterward, I also talked with him and let him know how awesome he did.
Thank you, that makes sense now. I guessed that you wanted him to notice what was going on but wondered why you didn't reassure him with your voice. Now I understand. 😊