A famous portrait of a supposedly scientifically-minded couple on the eve of the French Revolution, modest in their presentation and surrounded by lab instruments - and beside it an infra-red scan of the same painting revealing elements which were eventually omitted from the final work, even as others like the scientific instruments were added. Several of these elements seem in direct contradiction to our perception of the painting today.
https://files.mastodon.green/media_attachments/files/113/531/942/309/706/320/original/bb08d950e0a5d1b0.jpg