James David Lewis-Williams said this quote

The first two-dimensional images were thus not two-dimensional representations of three-dimensional things in the material world, as researchers have always assumed. Rather, they were ‘fixed’ mental images.

~ James David Lewis-Williams

Perhaps the most striking feature of the west European Upper Palaeolithic, one on which many writers comment, is a sharp increase in the rate of change. Compared with the preceding Middle Palaeolithic, a great deal happened in a comparatively short time.

~ James David Lewis-Williams

The notion that an image is a scale model of something else (say, a horse) requires a different set of mental events and conventions from those that perceive the social symbolism of red marks on someone’s chest.

~ James David Lewis-Williams

Around 30,000 years ago, in the Aurignacian, at the beginning of the Upper Palaeolithic, someone or some group in the Eyzies region invented drawing, the representation in two dimensions on the flat of the stone of what appeared in the environment in three dimensions.

~ James David Lewis-Williams