Stars, forks, and contributions all start with first impressions. A GitHub README that leads with a high-quality screenshot grid dramatically outperforms text-only READMEs in attracting contributors and users.

The most effective README grid layouts: (1) light mode + dark mode side by side (1×2): shows theme support instantly, (2) 3 key screens of your app (Strip of 3): homepage, feature page, settings, (3) feature highlight grid (2×2): each cell shows one distinct feature with a caption below.

For open-source projects, showing your project in multiple contexts (desktop, tablet, mobile in a responsive grid) signals professional-grade implementation and attracts trust from senior contributors.

GitHub Markdown supports standard image embedding with `` syntax. Upload your grid PNG to the repository itself (under `/docs/` or `/assets/`) and reference it with a relative path. This ensures the image is always available and versioned with the repo. Alternatively, upload to Imgur and link directly: though this creates an external dependency.

For the best layout in Markdown, use an HTML table to control image width and side-by-side placement, as Markdown native image embedding doesn't support inline layout.