I think the joke/insight here is supposed to be that hardcore Christians are basically the same as their Islamist counterparts; however, a few salient differences may be noted.
- The woman on the right is standing in front of green flags which represent the unity of political and religious power under Islam, whereas the woman on the left is standing in front of the flag flown by the world’s first secular republic.
- The woman on the right (Reem Slaleh Raiyshi) killed herself ten years ago in order to murder non-Muslims, whereas the woman on the left (Holly Fisher) has never been accused of killing anyone, whether in the name of her religion or for other reasons.
- The woman on the left is holding a Christian Bible, a book which has twice as many cruel passages as the book on the right, a Quran.
Facile moral equivalencies make great memes, but they are not the stuff of great minds.