The Django Unchained star revealed that it was only when he saw the film on screen and saw Joss had made a "visual comic book" that he understood the motivation behind the director's approach.
He said: "People had been waiting on a film like that for a very long time. Fortunately we had the pleasure of working for somebody who understands the genre better than I think anybody who's ever done it before.
"Joss is a comic book fan, he's an amazing creator of some of the most iconic things that we've seen on TV, like Buffy and Angel and all those things. And he has an intricate knowledge of what that world is.
"Because there were times we were doing things, I had no idea why he wanted them so specifically that way, because he was very specific about 'No don't do anything else just do this!' and I was like, 'Really?'
"And then once I saw it I realised he was actually making a visual comic book. Which is something nobody has ever done. And I think the most amazing thing that he did, was get the comic part of comic book right. And I think Joss made that very clear that we were doing something that's not only exciting but fun, and it should be funny."
Jackson is supporting the Jameson Empire Done In 60 Seconds competition.
He said: "Expressing oneself is always a good thing, to keep them from being frustrated by the artist trapped inside them."
::To enter go to jamesonempirediss.com. Closing date for entries is January 20, 2013.