When Mariah is persuaded to steal the "Mrs. Claus" outfit that belongs to the neighbor's Christmas display, the clothes are replaced with a yellow Hawaiian dress. Once she returns it, Mrs. Claus had a skirt/dress on, not pants like Mariah wore.
When the dog got loose from the leash and Mariah chased it all the way to the frozen lake, the leash wasn't on her hand, and it was too bulky to fit in her pockets. When she finally caught the dog, the leash suddenly reappears.