'Sly' director explains why he included life-like wax busts of Sylvester Stallone's famous characters in the documentary

• The new Netflix documentary "Sly" looks at the life and career of Sylvester Stallone.
• It shows life-like wax busts of Rocky Balboa, John Rambo, and Barney Ross from "The Expendables."

When visiting Sylvester Stallone for the first time, it became instantly apparent to director Thom Zimny that the star lives in his own mythology.

Scattered around Stallone's palatial estate, you'll find a giant statue from "Rocky" and other memorabilia from his blockbuster movies. There are also three giant life-like wax molds in the actor's office of the characters he's most known for: Rocky Balboa, John Rambo, and Barney Ross from "The Expendables."

"Sly," now available on Netflix, captures the 77-year-old Stallone at a reflective period in his life as he recounts to Zimny his rags-to-riches career. The director said that when he laid eyes on those busts, he knew he'd have to feature them in some way.

"The busts of all the franchises were all in his office on a bookshelf," Zimny told Insider. "I realized I need to film these in the most glowing way."

So Zimny took each one, put them in front of a black background, lit them perfectly, and shot them to portray them in their full glory.

"It would remind you of the power of the iconic image he created, it would trigger your own memories," Zimny said of why he felt featuring the wax busts would be important.

However, it also played into the director's major theme of the documentary.

"The film is giving you two worlds," Zimny said. "The icon and the real man."