Agent Skills: UI Image Rules

UI Image Rules

These rules apply to every image element regardless of project design-dna.

Dimensions

• Every <Image> or <img> MUST have explicit width and height props, OR use the fill prop
• Never render an image without dimension constraints -- this causes layout shift
• Use Next.js <Image> component with fill for responsive containers, or explicit dimensions
• Use the sizes prop to specify different image widths for different viewport widths

Object-Fit Rules

| Image Type | object-fit | When to Use | |------------|-----------|-------------| | Hero banners, card thumbnails, backgrounds | cover | Image should fill container, cropping is acceptable | | Logos, icons, product images on white | contain | Full image must be visible, letterboxing acceptable | | Avatars, profile photos | cover | Face-centered crop fills circular/square container |

• Never stretch images -- always use object-fit with object-position for aspect ratio mismatches
• For cover images, set object-position to control which part of the image is visible (e.g., object-position: center top for portraits)

Optimization

• Prefer WebP/AVIF via Next.js Image automatic optimization
• Set priority on above-the-fold hero images (LCP optimization)
• Use loading="lazy" (default in Next.js Image) for below-the-fold images

Alt Text

• Every image MUST have descriptive alt text
• Never use generic alt text like "image", "photo", "picture", or ""
• Decorative-only images use alt="" with role="presentation" -- but this should be rare
• Alt text should describe what the image shows, not what it is (e.g., "Team collaborating around a whiteboard" not "team photo")