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="Tankstelle_Scharnweber_Elektrohandel_Mesch_Kirchenstrasse_1950er.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="322" ns="6" title="Datei:Tamsen Friedrich, Eltern+Kinder.png" imagerepository="local">
        <imageinfo>
          <ii timestamp="2015-02-26T13:51:59Z" user="D.Ziemann" />
        </imageinfo>
      </page>
      <page pageid="397" ns="6" title="Datei:Tankstelle Autohaus Beckmann Bahnhofstrasse 1950er.jpg" imagerepository="local">
        <imageinfo>
          <ii timestamp="2015-03-08T18:52:50Z" user="Paap" />
        </imageinfo>
      </page>
      <page pageid="425" ns="6" title="Datei:Tankstelle Autohaus Rohlf 1950er.jpg" imagerepository="local">
        <imageinfo>
          <ii timestamp="2015-03-20T07:33:54Z" user="Paap" />
        </imageinfo>
      </page>
      <page pageid="423" ns="6" title="Datei:Tankstelle Autowerkstatt Looft Hamburger Straße 28a um 1960.jpg" imagerepository="local">
        <imageinfo>
          <ii timestamp="2015-03-20T07:22:34Z" user="Paap" />
        </imageinfo>
      </page>
    </pages>
  </query>
</api>