From SlashFilm, Matthew Vaughn is quoted describing the movie:
It’s definitely more serious and more realistic, and I think that’s something that had to happen. That’s my feeling about the world we live in right now. I think the glossy colorful superhero film sorta had its day. I think Batman Begins started it, Dark Knight, dare I say Kick-Ass was fun and it had some real pop to it, but at the same time we grounded it in reality as much as possible. I think that’s what the audience wants. And that why that image is more Fantastic Four than it is X-Men. And I say that with all due respect to the Fantastic Four team. That was then and this is now. It’s a different time.
Also, this picture:
Is a fake.
This is what Vaughn said about that low quality, photoshopped monstrosity:
I freaked out on them yesterday. I don’t know where the hell that came from. I don’t think it’s a Fox image. It’s not a pre-approved image. When I found out, I said, what the fuck is this shit, and Fox is running around trying to figure out what happened as well. I agree. It’s like a bad photoshop, which maybe it was by someone. It didn’t reflect the movie. I was shocked when I saw it. I was like ‘Jesus Christ’…