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>
    <images imcontinue="1|Spanish_lang.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Main Page">
        <images>
          <im ns="6" title="File:Assistant.png" />
          <im ns="6" title="File:Chinese lang bw.png" />
          <im ns="6" title="File:Editing.png" />
          <im ns="6" title="File:English lang.png" />
          <im ns="6" title="File:Japanese lang bw.png" />
          <im ns="6" title="File:Korean lang.png" />
          <im ns="6" title="File:Main page pic.png" />
          <im ns="6" title="File:Newspaper icon.png" />
          <im ns="6" title="File:Portuguese lang bw.png" />
          <im ns="6" title="File:Question orange.png" />
        </images>
      </page>
    </pages>
  </query>
</api>