Twilio's API allows users to send and receive media, including images, using WhatsApp. The application will use AWS Rekognition to analyze the images sent by users. The application is built using Ruby and Sinatra, with Twilio-Ruby for generating TwiML responses. Ngrok is used to tunnel down to the local machine from the public internet for testing purposes. The application downloads the image received via WhatsApp, analyzes it using AWS Rekognition, and responds back to Twilio with a message indicating whether any celebrities were detected in the image.