The fish symbol has been used by Christians for two millenia. It is an interesting coincidence that the fish could also represent the idea of pandeism. On the left of the diagram is an open-ended triangle symbolizing the original divine being condensing and collapsing into a point singularity, leading into the oval-shaped universe on the right. Pandeism could be the real original meaning of Christian doctrine.
The oval on the right of the image is a depiction of the Cosmic Microwave Background Radiation which is a remnant of the Big Bang.