It fails to get the favicon for kde.org but succeeds with other websites.
{F3779662}
Verified that it downloads the icon only first time and then uses the one from cache. Unfortunately this stuff is from a time before we had apple touch icon and co. so we only get the 16x16 icon :)
Future improvements would be to extract <title> and other information (there's a jumplist thing for websites) from the linked site but I couldn't figure out how to tell the mimetype of that http site with kio (statjob, even with details 2 just gave me octet stream in its kfileitem).