Below is an example of how to use the Social Sharing extended block:

<div class="jw-settings" id="my_simple_settings">
     <video id="my_simple_video" poster="/posters/big-buck-bunny-preview.jpg" preload="none">
          <source src="/videos/mp4/big-buck-bunny.mp4" type="video/mp4" data-bitrate="555000" data-width="360" />
          <!-- non-Flash fall-back sources -->
          <source src="/videos/mp4/big-buck-bunny.mp4" type="video/mp4"/>
     <div class="jw-modes">
          <div class="jw-mode" data-type="flash"></div>
          <div class="jw-mode" data-type="html5"></div>
     <!-- Extended Social Sharing Block -->
     <div class="jw-extended" data-type="sharing" data-code="%3Ciframe%20src=%22" data-link=""></div>

NOTE: The data-code attribute will be the embed code that you wish to display in the JW embed code overlay field – This should be URI encoded