On Friday, people in Wuhan city in central China’s Hubei Province discovered retrofitted platform screen doors on subway Line 6. /VCG Photo

When passengers are waiting for trains, the doors function as projector screens and showcase city highlights and commercials. Once the train arrives, the screens disappear and turn into mirrors. /VCG Photo

The design team behind the high-tech screen doors has applied for a patent for the invention and hopes to install more of them in the future. /VCG Photo