"The article is about a sexual act. I don't see what the problem is with porn in this instance, as long as the site itself contains lots of high quality free material (which this one does)."
The question is again one of minors accessing pages like this one and being shown porn sites through it. I see no difference between publishing porn and creating links to it, at least as far as responsible reporting on sexual matters goes.
It also, at least to a degree, threatens to render ineffective the removal of THAT picture.