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 aicontinue="BX01-004_7507-39-28_11w.jpg" />
  </query-continue>
  <query>
    <allimages>
      <img name="BF03-018_7506-039-33_11w.jpg" timestamp="2016-01-10T15:54:07Z" url="http://www.e-nebraskahistory.org/images/3/34/BF03-018_7506-039-33_11w.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BF03-018_7506-039-33_11w.jpg" ns="6" title="File:BF03-018 7506-039-33 11w.jpg" />
      <img name="BF14-024_9304-007-10_11w.jpg" timestamp="2016-01-10T15:58:49Z" url="http://www.e-nebraskahistory.org/images/3/35/BF14-024_9304-007-10_11w.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BF14-024_9304-007-10_11w.jpg" ns="6" title="File:BF14-024 9304-007-10 11w.jpg" />
      <img name="BINNEY_016.w.jpg" timestamp="2020-02-27T22:28:57Z" url="http://www.e-nebraskahistory.org/images/7/7b/BINNEY_016.w.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BINNEY_016.w.jpg" ns="6" title="File:BINNEY 016.w.jpg" />
      <img name="BL11_w.jpg" timestamp="2016-10-26T19:55:13Z" url="http://www.e-nebraskahistory.org/images/c/cc/BL11_w.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BL11_w.jpg" ns="6" title="File:BL11 w.jpg" />
      <img name="BL12_w.jpg" timestamp="2016-03-02T20:17:00Z" url="http://www.e-nebraskahistory.org/images/3/31/BL12_w.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BL12_w.jpg" ns="6" title="File:BL12 w.jpg" />
      <img name="BL13_w.jpg" timestamp="2016-09-16T14:08:07Z" url="http://www.e-nebraskahistory.org/images/e/e7/BL13_w.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BL13_w.jpg" ns="6" title="File:BL13 w.jpg" />
      <img name="BT198_201803_01.jpg" timestamp="2018-03-12T13:56:43Z" url="http://www.e-nebraskahistory.org/images/a/af/BT198_201803_01.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BT198_201803_01.jpg" ns="6" title="File:BT198 201803 01.jpg" />
      <img name="BU06-001_H673-5-5736_1w.jpg" timestamp="2015-11-12T16:31:53Z" url="http://www.e-nebraskahistory.org/images/9/9d/BU06-001_H673-5-5736_1w.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BU06-001_H673-5-5736_1w.jpg" ns="6" title="File:BU06-001 H673-5-5736 1w.jpg" />
      <img name="BVH_NewYearCard_1990_1w.jpg" timestamp="2017-11-30T21:55:25Z" url="http://www.e-nebraskahistory.org/images/0/00/BVH_NewYearCard_1990_1w.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BVH_NewYearCard_1990_1w.jpg" ns="6" title="File:BVH NewYearCard 1990 1w.jpg" />
      <img name="BVH_NewYearCard_1991_1w.jpg" timestamp="2017-11-30T21:51:13Z" url="http://www.e-nebraskahistory.org/images/d/d6/BVH_NewYearCard_1991_1w.jpg" descriptionurl="http://www.e-nebraskahistory.org/index.php?title=File:BVH_NewYearCard_1991_1w.jpg" ns="6" title="File:BVH NewYearCard 1991 1w.jpg" />
    </allimages>
  </query>
</api>