Why is self-portrait with palette by paul gauguin a post-impressionism piece of art?

( open-ended question )

Post impressionism established self-worth or symbolic and highly personal meanings. In this period, they were breaking away from academic art. This would fall closely to Cubism or Abstract expressionism. 

Answer the awkward tilt of the room and the linear brushstrokes on the floor (encourage the viewer into the space) this is all i could find, so plz check if it is right or wrong/// good luck