Unfortunately Scrum is too often explained and implemented that first way, leading to the anti-Agile feedback we see on HN with some regularity. The second way is much more compatible with complementary tools such as Lean Startup and Kanban and I wonder if this (to me very welcome) non-exclusivity explains why it is less talked about.
From what I can tell, it has all the meaninglessness of an empty buzzword used primarily as a method of trying to engage people and give an opening on selling their services by stating "oh if you don't understand the difference sit down with us and let us show you how different and better it is."
It looks like if scrum doesn't work they call it "falling left to right scrum", and if it works it's their "brilliant right to left scrum".
Even by their own definition they both have a backlog that gets prioritized and selected each 2 weeks into a sprint backlog, and executed during the sprint.
The rest is just hand waving. "One is goal focused vs the other is backlog focused. Oh yeah but we do put our goals in the backlog." So they're both backlog focused then? The only thing they're really sayings is "When prioritizing tasks, make sure they accrue to something and aren't just random work." Which is both obvious, and of course too simple to write and sell a book about, so instead this whole other terminology is made for it.
Thanks for sharing the link though.