The same way we can, and should, display pictures of what the Einsatzgrupen and other Nazi's did -- to make sure that people understand that there are vile, evil people who intend to harm others.
You are either an accomplished troll, or you're one of the most exasperating, willfully-ignorant people I've ever encountered. If you really thought that abortion is good, then you'd be posting pictures all day long, showing what bad things abortionists have gotten rid of. If I had a picture of my ex-appendix, I'd show it. "Look at that. The damned thing almost killed me." You could show one of your non-human babies and say, "Look at that. That damned thing almost cost me from having to find a babysitter while I go to night school."
If you'd like a more in-depth explanation (and you'll probably need a life jacket in any explanation more than ankle-deep), then please visit the Center for Bioethical Reform. While you're there, you may want to look at Planned Parenthood's back-alley abortions.
I am not going to follow that link just satisfy you ghoulish needs.
Protest all you want. Just know that everytime you show your pornography to someone who is not of like mind, they think you are very sick. Watch their eyes. You will see it there. The disgust you see is about you.