When I clicked this the title was asking how this was working. I think that's what this user was answering
https://news.ycombinator.com/newsguidelines.html
The submitted title was "Wall-climber robot spraypaints big murals, any idea how its hardware works?", which is actually more baity than the original (wrong direction!). It's also the sort of thing that will strike HN readers as transparently promotional, prompting them to flag a submission.