In this picture, the artist wanted to touch on two themes.
Tourists from all over the world come to see the great Mona Lisa. They run into the Louvre in a huge crowd, just to quickly take a meaningless selfie. They are not able to stop for a moment and enjoy the great picture.
On the canvas, the artist depicted a symbolic calendar with dates. He marked the date, July 25, with a red circle. This is the date of creation of this picture. Now the artist will cross out the past day every day until this picture is bought. This way the buyer can participate in the final image of the canvas. The artist encourages you to think about how hard it is to get money and how hard it is for an artist to sell their paintings. They can lie for years and decades, until the picture finds its audience, or they can disappear like useless trash.