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="Barleria_prionitis_(Porcupine_flower)_in_Hyderabad,_AP_W_IMG_9999.jpg|677" />
  </query-continue>
  <query>
    <allfileusages>
      <f ns="6" title="File:BCRT Logo-1.jpg" />
      <f ns="6" title="File:BLW Nandi, Siva&#039;s Sacred Bull.jpg" />
      <f ns="6" title="File:Babool (Acacia nilotica) flowers at Hodal W IMG 1163.jpg" />
      <f ns="6" title="File:Bachaur.jpg" />
      <f ns="6" title="File:Bael02 FSPark Asit.jpg" />
      <f ns="6" title="File:Bael04 FSPark Asit.jpg" />
      <f ns="6" title="File:Bandipur 2.jpg" />
      <f ns="6" title="File:Baraguru.jpg" />
      <f ns="6" title="File:Barleria prionitis (Porcupine flower) in Hyderabad, AP W IMG 9989.jpg" />
      <f ns="6" title="File:Barleria prionitis (Porcupine flower) in Hyderabad, AP W IMG 9989.jpg" />
    </allfileusages>
  </query>
</api>