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="B1_826.gif" />
  </query-continue>
  <query>
    <pages>
      <page pageid="407" ns="6" title="File:120px-BDSM-rights-flag-Tanos.svg.png" />
      <page pageid="410" ns="6" title="File:120px-Master Slave Pride flag.gif" />
      <page pageid="409" ns="6" title="File:120px-Ownership-flag-Tanos.svg.png" />
      <page pageid="406" ns="6" title="File:220px-BDSM logo.svg.png" />
      <page pageid="408" ns="6" title="File:220px-Leather, Latex, and BDSM pride.svg.png" />
      <page pageid="414" ns="6" title="File:52px-Kajira-kef.svg.png" />
      <page pageid="845" ns="6" title="File:562753 421186061266414 754677590 n.jpg" />
      <page pageid="413" ns="6" title="File:595px-Bear Brotherhood flag.svg.png" />
      <page pageid="860" ns="6" title="File:753af1765027c58b5ed0407f1dffb7a7.jpg" />
      <page pageid="269" ns="6" title="File:800px-BDSM acronym.svg.png" />
    </pages>
  </query>
</api>