That's the whole point though, and I think the article try to also point that.
That is, there are considerations which are harder or downright impossible to model when a scene is approached under some perspective. But change perspective, and everything might now be obvious if not completely trivial to handle. The additional information pointed here is that even if placed in the very same perspective, people will still perceive the situation differently. Even at the same position with the same light exposure, a color blind person won't experiment the same observation as someone whose cognitive process overload the mental picture with additional color information.