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="A._arenaria_leaf.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="11426" ns="6" title="File:20130812 131722.jpg" />
      <page pageid="11586" ns="6" title="File:2016-05-11 12.33.16.jpg" />
      <page pageid="11374" ns="6" title="File:800px-Beccariophoenix alfredii 45-1.JPG">
        <duplicatefiles>
          <df name="In_landscape_Beccariophoenix_alfredii.JPG" user="MOSES JONES" timestamp="2014-01-10T04:58:22Z" />
        </duplicatefiles>
      </page>
      <page pageid="11397" ns="6" title="File:86 Bismarkias with rock outcrop1.jpg" />
      <page pageid="11398" ns="6" title="File:87 Bismarkia inflorescence.jpg" />
      <page pageid="11399" ns="6" title="File:88 Bismarkia infructescence.jpg" />
      <page pageid="11400" ns="6" title="File:89 Bismarkias in situ1.jpg" />
      <page pageid="11401" ns="6" title="File:90 Bismarkia with open flowers.jpg" />
      <page pageid="11402" ns="6" title="File:91 Bismarkias on plain1.jpg" />
      <page pageid="11569" ns="6" title="File:A. arenaria 714.jpg" />
    </pages>
  </query>
</api>