Imagine a stage for dresses draped like costumes of ballet dancers performing on two floors. The Cortana store in Palma is a true showroom. Straight, elegant silhouettes of translucent materials in beautiful colors, neatly arrayed on metal poles that hang from the ceiling. The clear cuts, selected materials, and patterns are reminiscent of pieces of art. That comes as no surprise. Rosa Esteva studied art history and fashion design in Barcelona before she returned to Mallorca. She opened her…