The articles employs the concept of Affordances, which comes largely from JJ Gibson, a brilliant psychologist who studied perception.

I used to teach a course on Gibson... so I'd like to clarify what he meant by affordances, which is a bit more powerful of an idea than presented in the article

His insight was that how you perceive something is not objective, but subjective. Or as he would say, the subjective turns out to be objective reality. So affordances reflects the fact that how you relate to something is in terms of what it affords you. A good example: An excellent downhill skier sees a near vertical drop as easy-peasy and not dangerous. The same skier learning to snowboard pulls up at this veritable cliff and says, holy shit, that's steep! Same physical world changes depending on how you relate to it on the present circumstances

JJ Gibson used such ideas to overthrow the object reality idea of perception, suggesting that perception is inherently a being-in-the-world phenomenon, not an objective knowing of the world (that exists, but is secondary and stripped of subjective experience).