This is an animated Gif of Rebecca Black being denied a car seat by 50 Cent. Rebecca starts off by singing "Which seat can I take?" The next scene in the Gif shows 50 Cent laughing at her and driving away with Bert from Bert and Ernie on Sesame Street in the back seat.
Rebecca Black sprung to Internet fame last year when her song "Friday Friday" became the most disliked video on Youtube. Since then, she has been on the receiving end of a number of harsh jokes.