In many interviews, Joan Miro expressed contempt for conventional painting methods. He believed that these methods were a way of supporting bourgeois society. He famously declared an "assassination of painting" in favor of upsetting the visual elements of established painting.
Miro's works originated the Surrealist school and are expressive of dramatic emotion. For instance, Still Life with Old Shoe was painted while he was stranded by civil war in Paris. It expresses the negativity and suffering representative of the war: “Form for me is never something abstract. It is always a token of something ...."
Miro was painter who seemed not to want to be defined in a particular genre. While influenced by VanGogh, Miro experimented with many forms of art. Early works expressed "humor." He turned away from the chaotic of the Surrealists and moved to more realistic work, working with light and color, to produce pastoral paintings. Hemingway noted that Miro's work was able to capture the essence of Spain: what was beautiful about it and what was missed when one was away. Later work included elements of fantasy. These elements were present in his work in the Surrealist movement in the 1920s. Reading about Miro's art, it seems safe to say that he never completely aligned himself with one form of art, but tried and was inspired by many forms and many places.
Because he seemed not to want to be defined by a specific genre, and in light of his experimentation, I would agree with "accessteacher" that "identity" was an important aspect of Miro's work.
It is important to remember how identity plays such a key role in Miro's own view of himself and of his work. Let us remember that Catalans are fiercely independent and have their own distinct language and culture in Spain. Therefore, to a certain extent, we can see Miro's art as being an expression of that identity.
More specifically, he was Catalan, and he actually saw his work as an expression of ethnic pride. He stayed in exile when Franco rose to power, as the dictator actively persecuted Catalan intellectuals. He had a great deal of contempt for Picasso, whose work he saw as bourgeois, and identified with some of the more iconoclastic artists of his time, including Max Ernst, Salvador Dali, and the Dadaists.
Joan Miro was a multi-talented artist. He was a painter, sculptor, and ceramicist (he worked with ceramics). He was Spanish, born to artisans. His work is described as surrealist. He seems to have declared war both on traditional painting and on the upper class.