This is "Clothes on the Grass: Study for 'Bathers at Asnières' by Georges Seurat. You're looking at one of Seurat's early works, painted in 1883, and it's a study for his larger composition "Bathers at Asnières", which he completed just the following year.
Seurat was still experimenting with his technique at this point, but you can see that he's getting closer to developing the style we know as pointillism. This painting is interesting because Seurat painted it outdoors, in the open air, and it shows a lot of his attention to detail in capturing light and shadow.
The focus here isn't on the people, but rather on the landscape itself - the grass and the trees are almost more important than the discarded clothes in this study. It's a great example of how Seurat was thinking about composition and color even at this early stage in his career.
Clothes on the Grass: Study for 'Bathers at Asnières' hangs in The National Gallery on Trafalgar Square, London — free to enter. Point your phone at any artwork there and audioguide.london plays a free audio guide in six languages — no app download needed.