Gokudera isn't even noticing the shadows, just moving how Kaiba does, following without being lead to do so. It's so easy, and he hears the comment, gives a soft hum of acknowledgement, and then sits down as well. The entire time it seems he's maintained that even breathing. His eyes slip shut and he focuses on how he feels. Nothing felt odd or forced, just as much trust as if he were in complete control the entire time.