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="11th_Foot_2nd_bat._Regimental_Colour.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="3677" ns="6" title="File:10th Dragoons King Guidon.jpg" />
      <page pageid="3678" ns="6" title="File:10th Dragoons Regimental Guidon.jpg" />
      <page pageid="3676" ns="6" title="File:10th Dragoons Uniform Plate.jpg" />
      <page pageid="3221" ns="6" title="File:10th Foot King Colour.jpg" />
      <page pageid="3222" ns="6" title="File:10th Foot Regimental Colour.jpg" />
      <page pageid="3220" ns="6" title="File:10th Foot Uniform Plate.jpg" />
      <page pageid="3681" ns="6" title="File:11th Dragoons King Guidon.jpg" />
      <page pageid="3682" ns="6" title="File:11th Dragoons Regimental Guidon.jpg" />
      <page pageid="3680" ns="6" title="File:11th Dragoons Uniform Plate.jpg" />
      <page pageid="7131" ns="6" title="File:11th Foot 2nd bat. King Colour.jpg" />
    </pages>
  </query>
</api>