The shimmering Tiffany Dove Window is also referred to as the Holy Spirit Window designed by the famous stained glass artist Louis Comfort Tiffany. In the mid-1890s, The window was made and installed in the First Presbyterian Church of Springfield, Illinois, with whose congregation Abraham Lincoln worshipped for many years.
"Christ in Majesty" w/in mandorla = vesica piscis shaped aureola. "Mandorla" = almond nut in Italian. In Eastern Orthodox icons the mandorla is used to depict sacred moments which transcend time/space (Resurrection, Transfiguration & Dormition of Theotokos). mandorla are painted in several concentric patterns of color which grow darker closer to the center, in keeping with Apophatic theology: As holiness increases, there is no way to depict its brightness, except by darkness