YouTube video thumbnail, 16:9, photorealistic, ultra sharp, high contrast, vivid saturated colors, cinematic lighting. The woman is exactly the person from the first reference image: same face, same dark wavy shoulder-length hair, dark knit sweater. The creature is exactly the glowing teal sea serpent from the second reference image. No text, no letters, no numbers, no logos, no watermarks. Composition: on the left third, the woman framed from the chest up, facing the viewer with an amazed, wide-eyed expression, mouth open in awe, one arm extended pointing at the creature. On the right two-thirds, the enormous serpent rising out of dark churning water inside a stone lighthouse hall, its head close to the camera, glowing amber eyes, bioluminescent teal scales, spray and mist. Warm orange light on her face, cold teal light on the creature. Keep the bottom-left corner darker and uncluttered for a caption.
