Get favicon href url in a Google Sheet via importXML and xpath
/html/head/link[@rel='shortcut icon' or @rel='Shortcut Icon' or @rel='icon'][1]/@href
=image(ImportXML("http://www.smilesbygriffin.com", "/html/head/link[@rel='shortcut icon' or @rel='Shortcut Icon' or @rel='icon'][1]/@href"))