If masked means hidden, barefaced means unconcealed. If you get caught speeding and reach into your wallet and hand the officer $20, that’s a barefaced attempt at a bribe.
Barefaced — or as it's sometimes known, bald-faced — behavior is always bold and sometimes shameless. Nonchalantly telling a security guard at the jewelry store that you "plain forgot" you'd slipped the necklace into your pocket is a barefaced lie and shameless to boot. A reporter's barefaced questioning of a mayor found to be stealing from city treasury carries no shame, on the other hand — at least not for the reporter.