This is a step-by-step guide to building a CloudFront distribution that serves S3 media, performs on-demand image transformation, and authenticates incoming requests using Cloudinary. The process involves creating an origin-request Lambda function in TypeScript, adding dependencies, modifying the Lambda function to proxy requests to Cloudinary for transformations, deploying the function as a CloudFront Lambda@Edge, and attaching it to a CloudFront distribution. The guide covers topics such as query parameter handling, transformation of query strings, and response formatting, providing a detailed overview of the process.