Depending on places and codes of TV conducts "pornographic" is normally relating to people explicitly having sex while showing genitals. "Soft-porn" would be people having sex (or pretending to) without showing genitals but being generally naked. Obviously the real classification would depend on other factors (length of scene, realism, "voice" etc.).
The distinction is of any importance only regarding TV permissions, time of broadcasting, "rating" etc. It should never enter IMO the domain of artistic intent. Pornography can be "artistic" and there can be pornographic art in principle. Just like there can be erotic crap. Any field of human expression can yield artistic results, the appreciation of which is in any case entirely subjective. Art, like Science, must be free of any prejudice.
Saying that a work of art is "pornographic" can be a legitimate way to express a subjective aesthetic judgement (probably not very flattering) on that work. Less legitimate is categorizing works as "pornographic" as a way to censor them or to ostracise their author.
Some people call anything they don't like "pornographic". La dolce vita was defined pornographic by the old same idiots (typically wearing a black dress. Sometimes red. Exceptionally white).