For an analogy, I think of a functional car: In order for there to be a functional car, there simultaneously exist an engine, four wheels, a chassis, a tank with gasoline, all kinds of lines, a steering wheel etc., all those things needed for a car to be functional. In a functional car, all these components exist simultaneously, and are simultaneously needed for there to be a functional car. In a functional car, when there are four wheels, there is an engine; when there's a steering wheel, there's a chassis, etc.; the components can be paired up randomly, depending on our perspective and what we wish to point out, but they all need to be simultaneously present in order for there to be a functional car. The components also don't cause eachother: the engine doesn't cause the steering wheel, nor do the wheels cause the gasoline tank, etc.
(There is, of course, a point at which any analogy breaks down. But I think the above explains simultaneity and non-linearity.)