This is going to be mostly for me. At the Institute of Design, I am very familiar with the differences between industrial design, service design, interface design, human computer interaction, architecture, etc., and I've seen versions this visual more times than I can count.
These distinctions basically tell us what we design or how we design things. However, it is also important to think about why we design things.
From a 2009 article in Core77 there are lots of types of design activity: user-centered design, eco-design, design for the other 90%, universal design, sustainable design, interrogative design, task-centered design, reflective design, design for well-being, critical design, speculative design, speculative re-design, emotional design, socially-responsible design, green design, conceptual design, concept design, slow design, dissident design, inclusive design, radical design, design for need, environmental design, contextual design, and transformative design. Essentially the authors categorize these types into four main buckets: Commercial Design, Responsible Design, Experimental Design, and Discursive Design.
But what really is discursive design? Discursive design is design which challenges the intellect of the user. While "good design" fades to the background, discursive design deliberately tries to make the user think: it is a thought catalyst or a communication tool.
In the Hugh Duberly diagram above, discursive design would be in the same area as "critical design." Critical design is essentially "design as critique," which I believe is very close to the idea of discursive design. Critical design is opposite to "affirmative design" which reinforces the status quo.
To add onto this, there is also conceptual design, anti-design, radical design, design fiction, speculative design, and more. These are all variants on the same idea which is to make the user think.
I think this is a great piece of potential discursive design. People do not understand what it means to throw something away or use energy. It is simply to much of an abstraction to understand large numbers or the effects of many people together. A piece like this which would blow steam rings into the air over the city to communicate a physical quantity of waste being created would certainly fulfill discursive design's requirement of causing a conversation.