gistfile1.cs

            // Load the original image from disk
            using (Image originalImage = Image.FromFile(Server.MapPath("~/App_Data/" + file.FileName)))
            {
                // Apply the queued transformations to the original image
                using (Image newImage = filters.Apply(originalImage))
                {
                    return File(newImage.ToByteArray(), file.ContentType);
                }
            }

What about

using (Image originalImage = Image.FromFile(Server.MapPath("~/App_Data/" + file.FileName)))
using (Image newImage = filters.Apply(originalImage))  {
                return File(newImage.ToByteArray(), file.ContentType);
}

if you just don't like the indentation.