Complex sentence: It was probably commissioned by either Jehan Braque or, more likely, his wife Catherine de Brabant (possibly after Jehan's sudden and early death), and is the only van der Weyden triptych not painted for private, rather than public, display.
Split into simpler sentences: It was probably commissioned by either Jehan Braque or, more likely, his wife Catherine de Brabant-possibly after Jehan's sudden and early death. It is the only van der Weyden triptych not painted for private, rather than public, display.