I guess if you really, really need spelled out to you what's happening in the Throne Room, these kinds of flash backs could help. But I prefer leaving some ambiguity in Vader's thoughts at this point ... it adds a bit of suspense (in case you think he may not save Luke) and allows some interpretation and guesswork re: what really is going through that pasty skull*. And the flashback to Luke's line from about a minute before ... was just discordant.

* What I think was going through Vader's skull is no doubt very different than what this editor thought.