Stream an image to a mobile phone

I wrote a logic to stream an image to a phone where you can save it. The code works on the web browser. But when I tried it on the phone, it will save the image, but I cannot view the image. I think the image is too big on the phone.
 
When I save the image on the web browser, I noticed the image size is 2KB. The image size on the phone is 40KB. I copied the image that was generated from the web browser to the phone, and I was able to view it.
 
Am I missing something for the phone? Does the logic work the same on the phone?

   string mappath = Server.MapPath("~/TestData/test.jpg");
                   //Server.MapPath("~/images/CommImages") + "\\";
                  Bitmap bitmap = new Bitmap(mappath);
             
 
                using (MemoryStream ms = new MemoryStream())
                {
                   
 
                    // Send the encoded image to the browser

                    Response.BufferOutput = false;   // to prevent buffering 
                    HttpContext.Current.Response.Clear();
                    HttpContext.Current.Response.ClearHeaders();
                    HttpContext.Current.Response.AddHeader("Content-Disposition",
                             "attachment; filename=USPSTest.jpg");
                    HttpContext.Current.Response.ContentType = "image/jpeg";
                    bitmap.SetPixel(10, 10, Color.Red);
                
                    bitmap.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
 
                 
 
                }
                bitmap.Dispose();