It's an enamel pin featuring an angel and a demon toasting to the world, inspired by a scene from a TV series where an angel and a demon toast to the world, which in turn is inspired by a novel in featuring an angel, a demon, and the best explanation of the British monetary system ever written.
Designed by Jennifer Brozek and Alina Pete this pin is about 1 inch wide and tall. Originally just a convention exclusive now you can buy them online. Hooray!