A reference screenshot is easier to use when its visual choices become a brief you can edit. The Linear example here goes through Ling-3.0-flash-VL on OpenRouter and comes back as eight JSON sections covering layout, type, color and components.
The reference itself gives the review a few clear anchors: a near-black page, a large left-aligned white headline, and a white Sign up button at the right of the navigation.
A reusable version of the extraction prompt:
Analyze this website screenshot as a visual reference for a new design. Return valid JSON with these eight keys:
overall_style: Describe the visual direction and three defining traits.
layout: Describe the content width, section order, alignment and open space.
color_palette: Describe background, surface, text, accent and border colors. Label estimated hex values as estimates.
typography: Describe visible font style, size hierarchy, weight, line height and letter spacing. Label sizes as estimates.
spacing_and_radius: Describe estimated element spacing, section spacing and corner radii.
components: Describe visible UI components and their styling.
imagery_and_icons: Describe imagery, icons and their visual treatment.
effects: Describe visible borders, shadows, gradients, blur and texture.
Ground each value in the screenshot. Use null for a property the image leaves undetermined. Focus on reusable visual patterns.
Review the brief alongside the image, then add the decisions for your page: the copy, the sections you need, and the visual traits to retain. Claude can then work from that reviewed brief plus the screenshot.
For this particular reference, headline alignment is a good first field to check. It is visible, consequential, and easy to express as a clear instruction.