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="ALFA_Cup_32_side_2.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="6903" ns="6" title="Fil:20110616163139438 0002.jpg" />
      <page pageid="6904" ns="6" title="Fil:20110616163522423 0001.jpg" />
      <page pageid="20550" ns="6" title="Fil:6otcha!.jpg" />
      <page pageid="18896" ns="6" title="Fil:ALFA 18.jpg" />
      <page pageid="19678" ns="6" title="Fil:ALFA 29 -1.jpg" />
      <page pageid="19679" ns="6" title="Fil:ALFA 29 -2.jpg" />
      <page pageid="19677" ns="6" title="Fil:ALFA Cup 23.jpg" />
      <page pageid="19890" ns="6" title="Fil:ALFA Cup 31 side 1.jpg" />
      <page pageid="19891" ns="6" title="Fil:ALFA Cup 31 side 2.jpg" />
      <page pageid="20045" ns="6" title="Fil:ALFA Cup 32 side 1.jpg" />
    </pages>
  </query>
</api>