The original point of Silk Spectre was to poke fun at the fact that every, well pretty much every, female superhero is often little more then a pin up. The sex scene, with the flame thrower climax, is in the original comic books (with fire etc.) and it is "directed" in a way you know it's meant to be dramatic and over the top. Synders way of making it look as face and unrealistic as possible was the "slow motion porn" scene as you've said. Because nothing is more unrealistic then porn.SpiderJerusalem said:Zack Snyder doesn't have women in his films, he has pin ups written by boys for boys. For an example outside of Sucker Punch, look no further than Watchmen, in which he managed to take a deep, complex and strong female character and give her nothing to do but a slow motion soft porn sequence.
The portrayal of Silk Spectres mother was interesting, in the comic's she's sort of the original sex symbol. To the point that all she is scene for is something to have sex with, which is one of the reasons the Comedian attempts to rape her (please note here I'm not saying she deserved it or anything like that). But at the same time it seemed to be the fountain of all her self-confidence so she has conflicted views over her past, and still tries to push it onto her daughter. The younger silk spectre in the comic is better covered, but then again are all of the characters she doesn't have cool one liners like the comedian though, but in the film they've focused on the destructive effect that being a "sex symbol" superhero would have.
Suker punch however has no such defence and I agree that looking across a movie poster you can just tick of a few cliché male fantasies and "hollywood" telling men what we should find attractive.
The reason I think a wonder woman film may not work, at current, is because a lot of people go to see superhero films and imagine themselves in the role. I believe it is harder with a male to picture himself as a female, not due to some genetic lack of empathy of a differently laid out neurons, but because they've never had to do it before. When they've had years of pretending to be __________man. Also the number of women I know who read comics are often just appalled at the costumes (google Star Sapphire costumes for the most rediculous, and this is coming from a massive GL fanboy) and regardless of how detailed a back story they have some of it is lost, I feel, when you know the first few moments there in costume someone will so "look at the breasts on her."