Carol Vogel details the views of a guest curator at Atlanta’s High Museum who believes Leonardo da Vinci painted to figures in an alterpiece as studio assistant to Verrocchio:

The contrast between the work of the two artists was striking to Mr. Radke. “Verrocchio had a talent for observing nature, and these observations were more generalized in his work,” he said. “Leonardo, however, wasn’t content until every bone and every vein is seen on every figure.” What Mr. Radke saw when he examined two of the figures — a youth with a salver (or round plate) and a turbaned officer carrying a baton — was a different level of detail, making them look far more three-dimensional than the rest.

“They were produced just at the time Leonardo was becoming an independent artist,” he said.

The panel will be on view in the Atlanta exhibition, and detailed photographs and illustrations will show the differences between the figures. The discovery gives scholars several new historical details. “It tells us that Leonardo’s claim in 1482 that he was proficient as a sculptor as well as a painter is accurate,” Mr. Radke said. “It also shows that he kept his association with Verrocchio later than most of us thought.”

In Atlanta, Indications of Hidden Leonardo (The New York Times)