Masterpieces often hold secrets beyond their visual appeal. Leonardo da Vinci’s ‘The Last Supper’ reportedly contains hidden musical notes, while Michelangelo’s ‘The Creation of Adam’ may depict a detailed human brain. Van Eyck’s ‘The Arnolfini Portrait’ is rich with symbols of loyalty and fertility. Holbein’s ‘The Ambassadors’ features a skull reminding viewers of mortality. Van Gogh’s ‘Café Terrace at Night’ might allude to religious themes.