Ethan Nyholm was the IT manager. Adina Jacobs was the accessories buyer. Neither of them came from the technology industry, and that turned out to matter enormously. Nyholm had spotted the gap from a practical angle. He needed a bag for his laptop that wasn’t a stiff black briefcase. When he couldn’t find one, he slid the machine into a postal envelope and dropped it into his backpack. Jacobs, meanwhile, had spent years reading consumers for a l…