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>
    <allfileusages gafcontinue="BP7_AD1.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="30325" ns="6" title="File:BEFORE POST.gif" />
      <page pageid="30420" ns="6" title="File:BOM.jpg" />
      <page pageid="31062" ns="6" title="File:BOSSIE2015.png" />
      <page pageid="30592" ns="6" title="File:BP1.png" />
      <page pageid="21799" ns="6" title="File:BP10 CI.png" />
      <page pageid="30374" ns="6" title="File:BP2.png" />
      <page pageid="30281" ns="6" title="File:BP3 CL.png" />
      <page pageid="30182" ns="6" title="File:BP4 FO.png" />
      <page pageid="30263" ns="6" title="File:BP5 EP.png" />
      <page pageid="30532" ns="6" title="File:BP6 CB1.png" />
    </pages>
  </query>
</api>