@tea is correct but here are some other things that might work:
1) Publish to ReviewLink and add your client as a reviewer. ReviewLink is free because it’s included with any Lectora license.
2) Publish to HTML and unzip the files on a CD or USB drive. Internet browsers have security that might cause some issues with content launched from this type of media, so they probably cannot just click the index.html file (it may not work). We use a Chrome plugin to test HTML content locally. Your client could install this Chrome plugin and then point to the CD or USB drive to display the published title. Here is a link to the free Chrome plugin: https://chrome.google.com/webstore/detail/web-server-for-chrome/ofhbbkphhbklhfoeikjpcbhemlocgigb/
Hope this helps.