Zhongshan ancient village , why a QR code on door plates?

We visit an ancient village in Zhongshan , Guangdong. There are many old house, ruins, and a funny thing is their door plates is showing a QR code~
▶️ DTube

We visit an ancient village in Zhongshan , Guangdong. There are many old house, ruins, and a funny thing is their door plates is showing a QR code~