Several iconic companies have announced significant rebrandings in recent weeks, upending a series of commercial and cultural landmarks. When Katja Vogt considers a Jaguar, she pictures a British-made car purring confidently along the Italian coastline — a vision of familiarity that conveys “that dreaming, longing feeling we all love.”She’s not sure what to think about Jaguar now after the 89-year-old company announced a radical rebranding this week that featured loud colors and androgynous people — but no cars.