Wilde brings up the idea that the costumes and mannerisms of an actor “get[s] rid of any necessity for tedious descriptions” of their character. A play has the advantage of immediately depicting unfamiliar apparel and weaponry from a particular time and place. (It’s easier to get a sense of a 16th century clothing through a costume than through a lengthy written description of doublets and mandilions.) More importantly, the expression and demeanor of an actor serve to visually describe the character to the audience.
However, this is not unique to plays. Comic strips and graphic novels also show a character’s physical appearance while simultaneously revealing his/her personality within the action of the story itself. This can be used to great effect when the imagery in a comic contrasts or calls into question the meaning of the text.