Create a high-quality image of an adorable, sweet-faced little mouse with large, expressive eyes, looking extremely happy as it gazes out of a window. The mouse has soft fur and a warm, inviting light comes through the window, casting a cozy atmosphere. The background outside the window shows a peaceful garden with greenery and flowers. The overall mood should be heartwarming, filled with joy and tranquility, capturing the innocence and sweetness of the moment.