That looks like one of the little bowls that people of the orient place on their top step by the front door to keep evil away. They fill it with salt. It seems like every house has one somewhere, front door, back door, window seal. Kind of like the shi shi lions that are placed on each side of the driveway/doorway and some I've seen on the roofs. One Dragon/dog has it's mouth open to let in the good and the other has it's mouth closed to keep out the bad or maybe the one with the open mouth eatsup the bad what ever you get the picture. What a wedding gift.
They also believe evil travels in straight lines if they live in a T in the road they place a small sign that will change or redirect the evil. So if it's coming down the road it will not pass into the house or rice field, grave yard, park, school etc.........
Hope that helps
Kermit