This is the "Portrait of a Young Man" painted by Bronzino. The young man in this painting has been the subject of much debate among art historians, and unfortunately, his identity remains a mystery to this day.
Scholars have suggested that he may be Duke Cosimo de'Medici, who was Bronzino's principal patron, or possibly even two other artists, Pierino da Vinci and Francesco Salviati. However, each of these theories has its own set of problems, so we're left with more questions than answers.
One possible clue lies in the sculpture behind the pink curtain. The god Bacchus is depicted in the sculpture, which may or may not be related to the young man's identity. Bronzino often used accessories and costumes in his portraits that were relevant to the sitters' identities, so it's possible that this painting holds more secrets than we can currently uncover.
The "Portrait of a Young Man" was likely painted in the mid-16th century, around 1550-55, using oil on wood.
Portrait of a Young Man hangs in The National Gallery on Trafalgar Square, London — free to enter. Point your phone at any artwork there and audioguide.london plays a free audio guide in six languages — no app download needed.