Unnatural expression, awkward pose, distorted features, exaggerated smile, overly large eyes, unnatural lighting, unconvincing bubbles, lack of realism in bubbles, flat colors, mismatched perspective, harsh shadows, unrealistic proportions, dull or muted colors, lack of depth, unnatural interaction with bubbles, unbalanced composition, lack of details in rainbow, unrealistic rainbow colors, unnatural background blending, overly busy composition.