You need much more than a 20mm difference to make social-distancing people look like they're basically hugging, which is what the article is about. Either way,

You need much more than a 20mm difference to make social-distancing people look like they're basically hugging, which is what the article is about. Either way, none of this matters anyways because the whole point of the article is the compression effect, not where it comes from and in their case, it came from a telephoto lens, not a cropped wide-angle, so the terminology is entirely fine.