[signaturefish]

"Affordances" are a UI design concept - they're things that the design of an object makes you think you can do with that object, if that makes sense. In this context, door handles afford being pulled (because they stick out of the door and you want to pull the door, so you pull the handle), buttons afford being pressed (because they are small, often labelled with a function, and project above the surface they're embedded in), etc.

So yes, I think you're right that it's a word-play between the UI design concept and the cost of implementation concept.

[Joker_vD]

And in the modern UI, all those small "hints" at how the interface can be used are being steadily removed: links, buttons, text fields, etc. all pretend to be static text.