"Design a double bathroom featuring two sinks, a shared shower area, and a bathtub. The bathroom walls should be covered with rocket plaster, giving them a smooth, modern finish. Include built-in niches in the shower area and above the bathtub for storing toiletries and decorative items. Ensure the layout is spacious and functional, with a focus on minimalist design and clean lines. Use subtle lighting to highlight the niches and add a warm, inviting ambiance to the space.