Mermaid in a Sacred Chapel, Photorealistic

Photorealistic mermaid inside a grand, ancient chapel. A shallow pool covers the marble floor, reflections from stained glass dancing on wet stones. Sunlight streams through colored windows, painting the space in warm and cool tones. The mermaid has a shimmering blue-green tail, long flowing hair, and a modest upper body veil of sea spray and seaweed to keep it tasteful. She is partly upright, one hand grazing a stone column as if in reverence. Surrounding details include carved arches, wooden pews, an ornate altar, coral-adorned organ pipes, and drifting motes of light and mist. The scene blends sacred architecture with underwater fantasy, high detail, ultra-realistic textures: wet stone, glass reflections, scales, hair, and fabric-like seaweed. Cinematic lighting, wide-angle perspective, photoreal quality.