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="S20.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="132" ns="6" title="File:Cabrosha mug web.jpg" />
      <page pageid="65" ns="6" title="File:Emb.png" />
      <page pageid="63" ns="6" title="File:Felt orca.jpeg" />
      <page pageid="62" ns="6" title="File:First chenille.jpeg" />
      <page pageid="82" ns="6" title="File:NOAC 2015 cont.jpg" />
      <page pageid="80" ns="6" title="File:NOAC 2015 fund.jpg" />
      <page pageid="81" ns="6" title="File:NOAC 2015 fund mylar.jpg" />
      <page pageid="66" ns="6" title="File:Neckerchief.png" />
      <page pageid="83" ns="6" title="File:OA 100.jpg" />
      <page pageid="76" ns="6" title="File:Redwood 2013 NJ numbered.jpg" />
    </pages>
  </query>
</api>