According to Microsoft Copilot on Twitter, the company has introduced a new feature called Rotten Eggnog Mode, designed to add a playful and relatable personality to the Copilot AI assistant during the post-holiday season (source: @Copilot, Jan 1, 2026). This move highlights the growing trend of AI-powered platforms incorporating seasonal and mood-based personalization to enhance user engagement and retention. By tapping into users' emotional states and cultural moments, Copilot leverages AI to foster deeper connections, offering businesses an opportunity to differentiate their products through creative AI-driven user experiences.