Upload image is ok but it's just a virtual image ???

Question

I upload some images but it's just virtual images.Someone help me why it like this. This is my code:
 protected void Button1_Click(object sender, EventArgs e)
  {
  string filename = "";
  filename = FileUpload1.FileName;
  FileUpload1.PostedFile.SaveAs(Server.MapPath("images\\")+filename);
  }

and when i run it and then i press "show All files" button .It's just appear.
Like this: