The pics came from the unrated dvd version that I have of the film. Perhaps you have an 'R' or somehow censored/cut version of the film. I remember it being hard to track down my uncensored copy in the U.S.
The interviews I remember from the time indicated that the actual sex was simulated – he wasn't fucking the woman on set, just pretending to -- but when he steps back, that it is Stephen Dorff's actual soft, condom covered cock.
I found a discussion on imdb that seems to reference the interview I remember from way back then. The director (Lee Daniels - of "Precious", "The Butler", and U.S. television's "Empire" fame) had discussions with the US ratings board to find out exactly what he could show and not get an X or NC17 rating. Apparently a soft, condom covered cock was ok for an 'R' rating.
http://www.imdb.com/title/tt0396857/board/nest/70847951?p=2