Well, for the chicken to imitate shicken you have to tell him to do the following things
"die"
the chicken dies, as all shicken is dead. Unless it is "sushi shicken", the kind that you eat when their still coloring in pictures. But this has been found to be unhealthy because the shicken is not cooked well, still has hair, and it's shoes might become caught in your throat. So therefore "die" is the appropriate command.
"leave me alone"
The chicken promptly goes jump in the oven. It returns when it is done cooking.
"poop"
The chicken gets into fetal position, much like the chicken you can buy from a grocery store, or shicken that went through 1st degree burns.
"masturbate"
the chicken comes up to you and you begin eating it, much like the proper etiquette with shicken. Since Burger King is family oriented the gory entrails from the self-cooked chicken are censored, as cooking yourself is about as effective as cutting your own hair.