That rule applies to adverbs. The distinction is admittedly subtle, but this page lists the exception you cited (in rule 5), but also uses "friendly-looking" in

That rule applies to adverbs. The distinction is admittedly subtle, but this page lists the exception you cited (in rule 5), but also uses "friendly-looking" in an example (in rule 4): http://www.grammarbook.com/punctuation/hyphens.asp http://www.grammarbook.com/punctuation/hyphens.asp