This cartoon doesn't have as much of an impact without knowing what it's parodying. There is a painting by Albrecht Dürer called 'Praying Hands' that looks very similar to the picture depicted here, except the hands are praying out at the viewer. In this case, the hands have been switched to a middle finger going outward. Nothing explains what the artist is trying to say here better than social media.
While the 'Praying Hands' image is all about praying to and for others, the middle finger is a big F-You to the world. Instead of trying to spread love inward and outward, we've become so focused on shouting our own opinions. If you got in a Facebook argument recently, it's time to realize that you didn't change anyone's mind. All you did was made two people made.