Isso na página de manual do wget, que provavelmente explica o que você está vendo:
-k --convert-links
After the download is complete, convert the links in the document to make them suitable for local viewing. This affects not only the visible hyperlinks, but any part of the document that links to external content, such as embedded images, links to style sheets, hyperlinks to non-HTML content, etc.
Each link will be changed in one of the two ways:
- The links to files that have been downloaded by Wget will be changed to refer to the file they point to as a relative link.
Example: if the downloaded file /foo/doc.html links to /bar/img.gif, also downloaded, then the link in doc.html will be modified to point to ../bar/img.gif. This kind of transformation works reliably for arbitrary combinations of directories.
- The links to files that have not been downloaded by Wget will be changed to include host name and absolute path of the location they point to.
Example: if the downloaded file /foo/doc.html links to /bar/img.gif (or to ../bar/img.gif), then the link in doc.html will be modified to point to http://hostname/bar/img.gif.
Sem mais detalhes, é difícil ser mais preciso.