Why is Xiang Xiang’s Japanese Fans all Dressed in Black?

When Princess Xiang Xiang appeared on stage, there was a lot of clicking of shutterbugs. Everyone is enjoying the charm of Xiang Xiang up close and personal. Today there is also a Japanese fan group to wait for Xiang Xiang for the whole day, all in black tops. Do you know why the Japanese fans coming to Sichuan to visit Xiang Xiang collectively wear black? It is to make sure the glass does not reflect when they are shooting.