The helmer, who is best known for his work on American Beauty and Revolutionary Road, admitted that the scale of a James Bond film felt alien to him at first.
"I came from smaller movies. I've done movies on a bigger scale, but not as big a scale as this," Mendes told Entertainment Weekly.
"It's weird, because you come in and someone has already explored the role, and so you're not in that position of starting on equal footing.
"But I was very clear about what I felt he hadn't yet done. We thought exactly the same about where the character could be taken."
Asked whether Daniel Craig's Bond would be presented as "hot" in his third outing, Mendes responded: "How can you not present him as a hot individual? He is a hot individual!
"You mean, are there any bod shots? How can I put this? Yes, I guess there are moments when he is [hot], absolutely. But the truth is, it's tied in... There's a reason in the story why... I can't say."
A new photo featuring Craig and villain Javier Bardem was released last week.
Other recent photos have highlighted Bond's Honda motorcycle and Ben Whishaw as Q.
Skyfall will be released on October 26 in the UK and November 9 in the US. Watch a trailer below: