This film also famously uses matte painting in the harrowing skating scene where Charlie skates blindfolded, not realizing he's constantly near the edge and very likely could fall down. The illusory drop has been matte-painted, and Chaplin was never really in danger while filming this heart-stopping scene - in reality, there was just plain floor with a ledge for him to discern when to stop. This can be observed in the fact that, at one moment, Chaplin's back wheel briefly disappeared behind the painting. This most likely escaped the eyes of Chaplin, which could be the reason he left it in.