Do you want to view only the webpage content that was delivered securely
If your page is requestiong data from Insecure zone http:// you will see below warning.
" Do you want to view only the webpage content that was delivered securely "
Those data can be from Script, images or Iframe.
If you are accesing web using Https:// make sure, all requests requested by your page are coming from Https:// and not from http://.