I am an ex-prochoicer. I was pro-choice all my life until I got married and was pregnant with my firstborn. I thought an 'abortion byproduct' --using your term-- was just a 'blob of tissue'. It was not until I saw the sonogram of my first born (over 14 years ago) that the full impact of what being a proabort really meant. IMNSHO, those displays are appropriate. They show the 'abortion byproduct'. It's the TRUTH. What are the proaborts ashamed of? The 'byproduct' of their services?
Images of humans engaged in sexual intercourse display the truth about reproduction also. Many small children and indeed many adults do not know what it really looks like.
Many people would be shocked and disgusted to see such a thing on their public streets. It really does not matter what most people think about the message or messanger. Maybe, just maybe the disgust produced by see humans engaged in sexual interourse would prevent some teenage prganancies and thereby prevent some abortions.