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="Setup_amplitude.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="7" ns="6" title="File:Create Job 1.png" />
      <page pageid="8" ns="6" title="File:Create Job 2.png" />
      <page pageid="4" ns="6" title="File:Job Monitor 0.png" />
      <page pageid="3" ns="6" title="File:Job monitor.png" />
      <page pageid="59" ns="6" title="File:Licensing dialog.png" />
      <page pageid="39" ns="6" title="File:Property airfoil.png" />
      <page pageid="21" ns="6" title="File:Pviewer default v360.png" />
      <page pageid="22" ns="6" title="File:Pviewer multiple.png" />
      <page pageid="11" ns="6" title="File:Pviewer sg6043.png" />
      <page pageid="10" ns="6" title="File:Pviewer v360.png" />
    </pages>
  </query>
</api>