Before, I have had a picture removed that did not violate those guidelines, because it supposedly "suggested" sexuality, whereas other pictures have remained in the gallery that have violated those guidelines.

To the extent that the admins do apply subjectivity to the issue, I think it's nicer if the decision-maker would look before-hand to advise of its appropriateness, rather than letting it be posted, then yanking it and sending that letter that says "you did something wrong." I think most people would probably find the former much more polite and the latter more upsetting.