Dull cosmic backdrop, lack of celestial ambiance, unconvincing stardust, mismatched colors, lack of luminosity, unnatural lighting, flat space environment, unimpressive celestial effects, lack of depth, jarring colors, disjointed cosmic elements, absence of harmony, uninspired composition, mundane cosmic hues, poor interplay between mandalas and cosmos, lack of elegance, lack of celestial enchantment, generic cosmic backdrop