That someone is what Aristotle would call the proximate cause of my harm does not imply that that person is morally blameworthy for what I suffer. Moral blameworthiness requires either an intention to cause harm or a relationship through which one incurs special responsibilities. Intention is rarely a factor when images that injure are published. Pictorial stereotypes are rarely produced with malice or with the plan to cause harm to individuals or to the community. But, the power and influence of mass market media create special responsibilities for image providers to be aware of the harm that they do or could cause.
Power creates special moral obligations.
Any time that there is an inequality in power in a relationship, the more powerful party incurs special responsibilities in regard to the more vulnerable party. The clearest example of a power relationship is the parent-child relationship. I have particular responsibilities toward my son that I don't have toward those who aren't vulnerable to my power. For example, if I wear my Gay Rights button as I walk through the local city streets there is likely to be some individual who is offended by the pink triangle and its symbolic reference. I am not responsible for the harm that person suffers.