A close-up shot of a light-up jellyfish decoration against a dark background. The jellyfish, positioned slightly off-center to the left, glows with a vibrant blue light that illuminates its translucent, tentacle-like appendages. The light pulsates subtly, creating a dynamic visual effect. The background is entirely black, providing a stark contrast that emphasizes the luminescence of the decoration. The image appears to be captured in low light conditions, possibly at night, which further enhances the glow of the jellyfish.