ok here I'm explaining the joke:
in the picture is 2 people, a young actress Chloe Grace Moretz, and an older politician Hilary Clinton. Chloe represents my cat when I first bought it, as her youth represents how young my little kitten was when I first bought it. Hilary represents my cat now, as her old age represents my cat's aged state now. time flies by so fast that even our pets age!