From John 17:
"That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me.
"And the glory which thou gavest me I have given them; that they may be one, even as we are one:"
It's a symbol radical fundamentalist Islamics use to say "there is one God but Allah." This is really silly IMO. Here, see for yourself, here's Farrakhan doing it. Obama isn't in THIS photo but here's the article about the photo.
https://www.newyorker.com/culture/annals-of-appearances/the-politics-of-race-and-the-photo-that-might-have-derailed-obama