Here are 2 example reponses.
1)The first most notable change from realism towards a different approach was seen in the work of Eduard Manet with his piece Le Dejeuner sur l’herbe, on which besides of exposing a different subject (female nude) and even maybe of some moral matter. In his performance or practice he changes the realistic output and with an “unfinished” brushwork, not as detailed as it was used in the realistic genre. Incorporated a composition on which the setting is considered mundane made in a huge canvas, breaking away from the norms on which only important or historic subjects would be painted in such a large size. With Manet we observe the beginning of modern painting. The transition from realism to abstraction involves the shift in the approach towards color ie: (Henri Matisse and Vincent Van Gogh), shape (Picasso, Cézanne), in content some artists still focused in art as a medium for emotional expression as well as many moved more toward the innovation and perfection of technique and perspective.
2)There were several factors that led to the transition from realism to modern/abstract art. Several of the earlier signs included the philosophy of Art for Art’s Sake (Whistler, specifically his work, Nocturne in Black and Gold), which helped reinforce that art could exist merely for the beauty and technique, it required no justification to be. This was all going on while technologies were advancing, the industrial revolution was creating a middle class that were seeking art to decorate their homes. Then add to that the invention of photography, which could capture every detail of a moment; artists began to explore more ways to expand their technique and challenge themselves.
Both Whistler’s, Nocturne in Black and Gold, and Turner’s, The Burning of the House of Parliament, have similar elements of using light and color to create something beautiful, they were more abstract than was common for the time. It us funny that Nocturne in Black drew the ire of Ruskin, when The Burning House of Parliament, which uses similar technique, received his praise.
Manet is given the title of “Father of Modern Art”, he was a realist who used modern depictions of contemporary life. With Dejeuner sur l’herbe and Olympia, he created small scandals by transforming classic styled works into modern versions which seemed to scoff at past traditional styles.