Verbal Irony- when she said "Go tell that man we ain't a bunch of trees." feeling like the man taking the picture treated them them as if they wasn't human beings as well and didn't have a say in weather they wanted their pictures took.
I think the sarcasm occurred when Cathy said that she was going to write a story about how to use a hammer.
A man is in the yard taking pictures without the consent of the homeowners and when he is asked to leave he continues to come back and take pictures.
In the story Granny said that she was making her cake drunk which meant that she was making a rum cake
In the story Cathy said that people tried Grandaddy Cain because he was tall and quiet like a king.
I think the theme is treat others how you want to be treated because if Camera and Smilin was in the same situation they wouldn't want someone to film them without their consent.