Gothic Stained Glass Lancet

I am planning on giving my AP Art History Teacher a Lego gothic stained glass window for his end of the year gift. He loves teaching us all about gothic style architecture so I thought this would be the prefect gift. I am planning on making it taller once I order more pieces, but I need some suggestions on how to improve my design first. I built a rough model on what I am planning to do. I will get enough pieces to make three lancet windows. Any suggestions on how to improve it or make it...