Diego Velazquez painted two portraits of this unknown sitter. The other has no lace and is more revealing. That is because a 'modesty' law had been introduced, forcing to paint a less 'revealing' pose. It has always struck me that V. seems to have had strong feelings towards her. Her gaze in both portraits has an erotic quality.
Diego Velázquez. El príncipe Baltasar Carlos a caballo. 1635. Museo del Prado. Madrid.