Generate a hyperrealistic 5-second video with 4K HD cinematic-quality realism. {Camera shooting pixel parameters: 1.6}, natural image noise level: 3.0, {realism parameter: 1.6}. The transition between light and shadow is seamless, and the proportions of the human body are perfectly accurate. {The protagonist’s hairstyle, facial features, biometric characteristics, and pose remain 100% consistent with the reference @image: 1.6}. [First Frame] The first frame remains unchanged. [5-Second Video Frame] Fixed Shot Total duration: 5 seconds, with a strong emphasis on the infectious power of the protagonist’s hearty laughter: 0–1 second: Maintain the first frame. 1–2 seconds: Fixed shot—The protagonist looks directly at the camera. Only the facial muscles move naturally; both corners of the mouth slowly rise upward, starting with a slight, restrained smile, then gradually widening into a gentle, warm smile. The cheeks’ apple muscles slowly lift upward, revealing a soft, subtle smile. The eyes appear gentle and filled with joy, transitioning smoothly from calmness to ease. The scene’s lighting remains unchanged. 2–5 seconds (the core laughter segment): Keep the camera position fixed, with a very slight, synchronized shift following the protagonist’s head movements. The protagonist’s smile rapidly expands, the mouth opening naturally wide enough to reveal the upper teeth and pink tongue. The jaw relaxes and opens slightly, and the head tilts back gently with the force of the hearty laughter. Both shoulders exhibit subtle, natural tremors in sync with the breathing rhythm of the laughter. The hair sways softly and naturally as the head tilts backward. The eye muscles contract naturally, forming crescent-shaped eyes, with natural dynamic laugh lines appearing at the corners of the eyes. The eyes narrow slightly due to the intensity of the laughter, while the apple muscles bulge dramatically, lifting the cheeks upward. The nasolabial folds become subtly visible, creating an intensely infectious, heartfelt, and genuine expression of open-hearted laughter. The demeanor is authentic and relaxed, without any trace of forced performance. The emotion is vibrant, bright, and radiates healing energy. The background remains blurred throughout, and the lighting stays warm and soft, maintaining an overall atmosphere that feels light and real. Throughout the entire sequence, the movements flow naturally and seamlessly, with expressions evolving gradually and convincingly. The laughter feels genuine and unforced, the skin texture appears natural, and the details are meticulously rendered.