A pop-up living room, tucked away in the corner of the Muller Lobby, this week quickly became a cozy oasis for students looking for a quiet spot for lunch or study. Students in a scene-design class created the temporary installation out of props that had been in storage. They used the oil portrait of Josephine Muller as a starting point, and added a fake fireplace, sofa, coffee table and rug. The pop-up installation is the latest in a series of pop-ups that is being created by students in the Upper School arts and theater classes. Seth Schmitt-Hall, Upper School Technical Theater Director, said the pop-up living room will be taken down on Friday. “That’s the beauty of theater,” he said. “It’s so finite.”