Bill Clinton’s Portrait Artist Secretly Includes Monica Lewinsky See what he did to the painting.

 -- Here's one issue the Clintons may -- or may not -- not want to brush off.

The artist who painted the official portrait of President Bill Clinton that hangs in the National Portrait Gallery in Washington, D.C. has revealed a surprise -- the portrait “subtly” incorporated Monica Lewinsky.

Artist Nelson Shanks says that the shadow on the left side of the portrait was cast by a mannequin in a blue dress -- a nod to the president’s affair with his 22-year-old intern.

“The blue dress itself doesn't appear in the painting,” Shanks told ABC News. “Only the shadow, which is symbolic of a shadow across the administration.”

Shanks, who described Clinton to the Philadelphia Daily News as “probably the most famous liar of all time,” says the former president never saw the shadow when he posed for the portrait in the Oval Office.

Shanks added the shadow in the painting later, in his Philadelphia studio.

“It was meant to be subtle and I think it is subtle,” he said. "I mean, I am doing historical documents in a way."

At the time of the portrait’s unveiling, Clinton thanked Shanks for the portrait, calling him a “great talent.”

The portrait is one of 55 Clinton portraits that are rotated at the National Portrait Gallery in Washington, D.C.

The portrait is currently not on display, but it is in the museum’s gallery of collection.

A museum spokesperson told ABC News that they have not received any requests from the Clintons to remove the portrait.

The portrait originally stirred controversy when it was released in 2006 for the notable absence of a wedding ring on the President’s hand.