You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <allimages gaicontinue="Cspadmetrology.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="70" ns="6" title="File:20140207021640!phpjp7Piq.png">
        <duplicatefiles>
          <df name="20140207070222!phpuaVgb9.png" user="Maintenance script" timestamp="2014-07-09T20:16:47Z" />
          <df name="20140207070950!phpZTThFK.png" user="Maintenance script" timestamp="2014-07-09T20:16:47Z" />
          <df name="Imbox_notice.png" user="Maintenance script" timestamp="2014-07-09T20:16:47Z" />
        </duplicatefiles>
      </page>
      <page pageid="68" ns="6" title="File:20140207070222!phpuaVgb9.png">
        <duplicatefiles>
          <df name="20140207021640!phpjp7Piq.png" user="Maintenance script" timestamp="2014-07-09T20:16:47Z" />
          <df name="20140207070950!phpZTThFK.png" user="Maintenance script" timestamp="2014-07-09T20:16:47Z" />
          <df name="Imbox_notice.png" user="Maintenance script" timestamp="2014-07-09T20:16:47Z" />
        </duplicatefiles>
      </page>
      <page pageid="69" ns="6" title="File:20140207070950!phpZTThFK.png">
        <duplicatefiles>
          <df name="20140207021640!phpjp7Piq.png" user="Maintenance script" timestamp="2014-07-09T20:16:47Z" />
          <df name="20140207070222!phpuaVgb9.png" user="Maintenance script" timestamp="2014-07-09T20:16:47Z" />
          <df name="Imbox_notice.png" user="Maintenance script" timestamp="2014-07-09T20:16:47Z" />
        </duplicatefiles>
      </page>
      <page pageid="5" ns="6" title="File:750.png" />
      <page pageid="58" ns="6" title="File:Ambox notice.png" />
      <page pageid="59" ns="6" title="File:Ambox speedy deletion.png" />
      <page pageid="61" ns="6" title="File:Cctbx logo small.png" />
      <page pageid="145" ns="6" title="File:Cppxfel dials after threshold.png" />
      <page pageid="144" ns="6" title="File:Cppxfel dials spot finding parameters.png" />
      <page pageid="143" ns="6" title="File:Cppxfel dials threshold before.png" />
    </pages>
  </query>
</api>