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="Be9ccdfe0cea820dd32ac58d78e10b09.jpg" />
  </query-continue>
  <query>
    <pages>
      <page ns="6" title="File:Babuskur (640x480).jpg" missing="" />
      <page pageid="958" ns="6" title="File:Baby chair1.JPG" />
      <page pageid="959" ns="6" title="File:Baby chair2 600.JPG" />
      <page pageid="960" ns="6" title="File:Baby chair creation1 600.JPG" />
      <page pageid="961" ns="6" title="File:Baby chair creation2 600.JPG" />
      <page pageid="1324" ns="6" title="File:Balsfjorden &amp; Lyngsalpene summits.jpg" />
      <page pageid="4544" ns="6" title="File:Bande logos régionaux fds 2013.jpg" />
      <page pageid="845" ns="6" title="File:Barustigur1.png" />
      <page pageid="6193" ns="6" title="File:Bastidor salma 38-760645.jpg" />
      <page pageid="6071" ns="6" title="File:Basw.png" />
    </pages>
  </query>
</api>