The fun has to do with the card game. Grandmother is thinking what to do with the card on her hand, possibly thinking a better way to keep the card. The granddaughter is laughing because she is winning.
It would be rude to laugh if they were friends, so they are family. The grandmother’s name is Mabel and the granddaughter is called Tessie. Mabel looks like she can take on anything; she is an indomitable lady.
They enjoy each other’s company most of the time. Grandmother may be losing, but Tessie is having fun. They are playing in Mabel’s home in her sitting room. There is a surprise tea party to be served with cake, oolong tea, and ginger ale. They get together often to brag about their grandchildren, play cards, and have tea; but when grandmother is not very happy then they don’t get together that often. Mabel knows she is losing the game; Tessie is laughing because Grandmother made a mistake.
Mabel is pleased with the young boy who is in the picture, because he is a diligent boy. All we need is somebody on the other side of the table to yell “Yea!” since somebody is winning. Next they eat all the cake!