I’ve been kicking around the idea of using some 1/2” plywood or foamboard to hide the frames of newly installed picture windows. Then fill in the gap with spray foam and bury it behind wood trim. I attached a render of the concept and a photo of the existing window. plywood/foamboard in white, sprayfoam in yellow, frame in red and drywall in grey. 

No idea if it’s a good idea, but I would like the look, it would also help me hide the wiring for the custom environmental sensor/automatic window shade that I am designing to install at the top.