Having admired diamond-shaped windows in stately old Syracuse houses, designer Thom Filicia introduced several in this lake house bedroom in Skaneateles as a repeating motif: "I like how they float in a wall." This one punctuates a screen wall between master bedroom and shower. On the bed, an orange duvet from Serena & Lily warms up a blue one from John Robshaw. The adjoining bathroom has twin Kohler vanities and Arhaus mirrors.