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>
    <allfileusages gafcontinue="Summit_meeting_between_Wendy_the_Weasel_and_Percy_Plush_in_Brussels_(July_2014).JPG" />
  </query-continue>
  <query>
    <pages>
      <page ns="6" title="File:Cancunchyk.jpg" missing="" />
      <page ns="6" title="File:Erminig avec un sous-bock Wikipédia.jpg" missing="" />
      <page ns="6" title="File:Henry, Peter the WikiPlaytpus and friend.jpg" missing="" />
      <page ns="6" title="File:Percy, répondeur téléphonique, Wikimédia France.jpg" missing="" />
      <page ns="6" title="File:Petit tigre on the top of Manhattan.jpg" missing="" />
      <page ns="6" title="File:Rory intro colored 02.jpg" missing="" />
      <page pageid="29" ns="6" title="File:Erminig - May 2014.jpg" />
      <page pageid="36" ns="6" title="File:Les peluches font du géocaching - Toulouse.jpg" />
      <page pageid="27" ns="6" title="File:Russell the Skunk.jpg" />
      <page pageid="26" ns="6" title="File:Shaxal - Wikimania 2014.jpg" />
    </pages>
  </query>
</api>