Here is a really enjoyable presentation about two medieval choir screens, one of the early 13th century at the abbey of St Mary in Vezzolano, in the northern Italian Piedmont region, the other of the later 15th century at the church of St Stephen in Breisach am Rhein, Germany. The narrator, Prof. Jacqueline Jung of Yale University, does a really marvelous job of explaining how the faithful would have interacted with the rood screens as part of the whole church, and how the screens themselves interact with the arrangement and decorations of the rest of the building. (h/t to reader Richard Seto for bringing this to my attention.)