This page demonstrates the ability to send images via the Image Optimization. Inspecting the URL of the above image will show how image manipulation parameters are passed using the query string.
sub vcl_recv { #FASTLY recv // Send the request to the IO set req.http.X-Fastly-Imageopto-Api = "fastly"; }
//facepug.io/images/a1/cat-best.jpg?crop=660:438&width=660