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="Fat-cat-300x268.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="153" ns="6" title="Fil:1013218 10152841297199579 6316834018579896296 n.jpg" />
      <page pageid="151" ns="6" title="Fil:10592969 10152755355740325 3548846312922674213 n.jpg" />
      <page pageid="150" ns="6" title="Fil:10731169 10152755340235325 741512825864352465 n.jpg" />
      <page pageid="149" ns="6" title="Fil:10847893 10152895784910330 9008552833388868993 n.jpg" />
      <page pageid="152" ns="6" title="Fil:1932317 10152253630640325 2097002032 n.jpg" />
      <page pageid="148" ns="6" title="Fil:B9ed022a9cd256e18bb1fbca5046495e.jpg" />
      <page pageid="181" ns="6" title="Fil:BKB logo.png" />
      <page pageid="46" ns="6" title="Fil:Crystal Clear action configure.png" />
      <page pageid="51" ns="6" title="Fil:Eksempel.jpg" />
      <page pageid="146" ns="6" title="Fil:Fat-Cat-Facts-pets-pet-cat-Cats.jpg" />
    </pages>
  </query>
</api>