Artists use various techniques to describe, or give the illusion of, three-dimensional space. Artists also sometimes deliberately try to deny the illusion of space. This set of artworks gives some examples.
Because it is natural to interpret flat patterns as solid objects, some artists deliberately try to work against this illusion.
The artist has tried to make this painting work as a painting, without necessarily referring to anything else. Nevertheless, it is almost impossible to look at the shapes and colours without thinking of some as being closer, or further away, than others. Which parts seem to come forward to you? Which seem to pull away?
This painting demonstrates how easily the illusion of space happens in our brains. The three red rectangles seem to sit in front of the cream-coloured 'background', whereas in fact they are almost exactly on the same plane. Perhaps if the rectangles were a different colour, they might look like holes.
Western perspective is just one method of describing three-dimensional space. Here are two others.