If a stylesheet comes from a different location as the html file that is including it the urls to images are fetched relative to the stylesheet.
As the test shows url("someimage.jpg"); should be replaced with url("testfiles/someimage.jpg"); but only if it is a relative url.
If a stylesheet comes from a different location as the html file that is including it the urls to images are fetched relative to the stylesheet.
As the test shows url("someimage.jpg"); should be replaced with url("testfiles/someimage.jpg"); but only if it is a relative url.