This painting represents polarisation. People often think differently about certain subjects. That something is a good thing or not at all or that something should stay that way or not.
Green stands for right and red for wrong. In this work of art you notice a great contrast between those two colours. When you look at this painting you feel you have to choose between the two, you are in the middle of the discussion.
But what is good and what is bad? Actually, it is relative. Good and bad are different for each person. Similarly, people may have heard different views and arguments from one side from an early age. This can have consequences that later they never want to listen to the other side and they don't actually form their own opinions.