The individual nodes for the items are contained inside the <xml> node (single item) or <object> node (multiple items). The content of these nodes depends on the type of objects returned and the structure of those objects in your schema.
Here are a couple of examples for an image and a video object:
<image
nav:objectType="image"
id="obj28130"
name="41.twig with snow.jpg"
creationDate="2009-02-11T20:54:30.933Z"
modifiedDate="2010-01-14T23:30:24.260Z"
author="Laura Koval"
eventDate="2009-02-11Z"
pixWidth="410"
pixHeight="307"
...
<thumbnail id="data2127" mime="image/jpeg" nav:mimeExt=".jpg"
nav:mimeMacType="JPEG" size="16634"/>
<preview id="data2128" mime="image/jpeg" nav:mimeExt=".jpg"
nav:mimeMacType="JPEG" size="68049"/>
<data id="data2129" mime="image/jpeg" nav:mimeExt=".jpg"
nav:mimeMacType="JPEG" size="138888"/>
</image>
<video
nav:objectType="video"
id="obj32771"
name="Reuters UK-BURBERRY [143857]"
creationDate="2009-09-23T22:13:50.863Z"
modifiedDate="2009-09-23T22:13:50.863Z"
author="Reuters, SEP 23"
eventDate="2009-09-23Z"
...
<thumbnail id="data6206" mime="image/jpeg" nav:mimeExt=".jpg"
nav:mimeMacType="JPEG" size="7471" />
<preview id="data6207" mime="image/jpeg" nav:mimeExt=".jpg"
nav:mimeMacType="JPEG" size="14373" />
<videoPreview id="data6208" mime="video/x-flv"
nav:mimeExt=".flv" size="4472423" />
<data id="data6209" mime="video/x-ms-asf"
nav:mimeExt=".asf" size="6537328" />
</video>