The main idea of coordinating artwork is to place two different pieces, that have something in common. They should have a thing that links them. It can be the color scheme or the theme. The two of them can be placed next to each other, or like in many cases on the both sides of a certain object. This helps achieve visual balance in the space.
Coordinating artwork is a great way to decorate a large wall, that you can’t decorate with a single piece. Gallery wall is another alternative. But if you don’t have the space to do it or you find it not appropriate for the space, you should go for two ones.