Hugin knocks at a window with his beak until someone comes to let him in to see Thor. He carries a package, unmarked, but based on the green and gold wrapping, it's probably from Loki. The package is spelled to prevent anyone other than Thor from opening it.
Inside, Thor will find a white square of paper and a Thor-themed snow globe. The paper carries Loki's signature and nothing else. The gift is his way of thanking Thor for the cooler weather.