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="160mm3mmx50mmCPlate.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="2660" ns="6" title="File:-Group 1--DSC02713 DSC02733-21 images.jpg" />
      <page pageid="1958" ns="6" title="File:0-web-tete.jpg" />
      <page pageid="1959" ns="6" title="File:1-web-tete.jpg" />
      <page pageid="1968" ns="6" title="File:10-web-tete.jpg" />
      <page pageid="3884" ns="6" title="File:10 touch control usb.jpg" />
      <page pageid="1975" ns="6" title="File:11812605916007.gif" />
      <page pageid="3886" ns="6" title="File:11 connection plugins en.jpg" />
      <page pageid="3887" ns="6" title="File:12 connection pilotes en.jpg" />
      <page pageid="3892" ns="6" title="File:14 connection preference systeme en.jpg" />
      <page pageid="3893" ns="6" title="File:15 connection bluetooth en.jpg" />
    </pages>
  </query>
</api>