Premise (noun)
- something assumed or taken for granted
https://www.merriam-webster.com/dictionary/premise
In the reading, “How better photos can help you document, and shape, your neighborhood” the author, Patrick Sisson said: “It’s premised on the notion summarized by a quote from Jonathan Raban, that, “the city as we imagined it, the soft city of illusion, myth, aspiration, nightmare, is as real, maybe more real than the hard city we can locate on maps.””
In other words, Patrick Sisson is trying to refer to a quote from Jonathan Raban who once said the city meaning New York could be a nice place based on people who travel here. However, what they don’t know is that this world the world we live in is an “illusion, myth, aspiration, nightmare” and it is true.