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 afcontinue="BackTrack_Inlay_Back.jpg" />
  </query-continue>
  <query>
    <allfileusages>
      <f ns="6" title="File:Baccarat Inlay.jpg" />
      <f ns="6" title="File:Baccarat Manual01.jpg" />
      <f ns="6" title="File:Baccarat Manual02.jpg" />
      <f ns="6" title="File:Baccarat Screenshot01.png" />
      <f ns="6" title="File:Baccarat Screenshot02.png" />
      <f ns="6" title="File:Baccarat Screenshot03.png" />
      <f ns="6" title="File:Baccarat Screenshot04.png" />
      <f ns="6" title="File:Baccarat Screenshot05.png" />
      <f ns="6" title="File:Baccarat Screenshot06.png" />
      <f ns="6" title="File:Baccarat Tape.jpg" />
    </allfileusages>
  </query>
</api>