When we look at a scene, we are constructing an understanding of what we see from past experience (is that a tree on the horizon or a pylon?). We can’t look in two directions at once, we have to take time to construct the picture (we look over here, then over there – even if we don’t move our head, our eyes scan the scene).
Yet we perceive this as experiencing the landscape in ‘the present’. This is sometimes called the ‘spurious present’ – “the interval of time such that events occurring within it are experienced as present”. This is by contrast to the ‘real present’ which is supposed to be dimensionless.In the diagram, the point at which the two cones meet (at the observer) is supposed to represent the real (objective, dimensionless) present.