Can you guess what is taking place in this illustration from a liturgical book? Please give your answer in the comments, and give whatever detail you can about the context, and the type of liturgical book from which the image is taken. To make this more interesting, please make your answer in the combox before reading the other comments.
Permission to use this image has been very kindly granted by the courtesy of the Pitts Theological Library, Candler School of Theology at Emory University. (Going to their website to look up the answer totally counts as cheating; I may never know, but God will!)
