Christmas morning is a time for blowing minds with amazing new toys and playthings. But after all the excitement, you end up with a bunch of wrapping paper and depressingly empty boxes that once held such promise. Christmas morning is the best morning of the year, but Christmas evening is the furthest you will ever be from the next Christmas morning. Dave is not immune to human-like waves of emotions like this.
Here you can see him disappointed to find no tuna in this box. Whatever tuna or toys it once held are long gone, or at least stuck underneath the furnace. Even Jack can't bring himself to get in this box.