In traditional urban public space, individual users can impact on space is limited. On the one hand, the transformation space or urban interface is quite complex and expensive project. On the other hand, due to the publicity of city, any change in it must be conformed to the public interest. Design and operating city is necessarily a task of the powerful capital and execution sector, while residents can only passively to accept and adapt to their city space. 

The emergence of large LED screen brings a little bit of change. The first piece of electronic bulletin board "Spectacolor" appeared in New York in 1978 was operated by a commercial company. The public can buy time from the company to broadcast any information on the screen. Compared with the traditional city interface, dynamic images of the large LED screen shows diversity and cost less when switching contents, which benefits the public. Although there is 5 minutes only, this moment belongs to the public, they can enjoy this it and share bless.

From the graffiti on the wall, to sketch a mark on some famous views, people urge to express themselves to urban public space. The existence of individual value was completely drowned out in the complex and huge urban society. The public is eager to leave personal thought in the city, thus building local sense of belonging. Large LED display provides a chance for ordinary users to change their city space, even it is a temporary change, also to some extent reflects the technology and more respect for the individual.