This is clearly someone fighting for a political position.
It also affected me deeply the first time I saw it. In fact, I've long held people should be required to see Till's face. It is my go-to image when I think of bigotry of any kind.
Emotional appeals are usually a weaker form of argument, but I'm not sure they are inherently immoral (except in certain circumstances). They may even have a place: regard for the suffering of others is not necessarily a bad thing when making a decision. Rather, the end they promote makes them moral or immoral. Abortion is, in my opinion, a less important issue and easier to argue the benefits of than, say, racism or global warming. There is basically consensus that global warming is bad (even those who don't believe in it would say, if it were real, it is a bad thing) and Nazism is bad and racism is bad. Not so for abortion.
Similarly, aborted children represent more complex equations for suffering and gain than global warming or racism. Does the fetus even feel? What about the overpopulation issue? What did the mother gain?
This sounds a bit ends justifies the means, but it doesn't mean I necessarily condone the any means necessary position. But that's another discussion.