I thought his reformulation of the film (and writing) rule of "show, don't tell," into "do, don't show," for games was an interesting idea. I'm not totally convinced it should be looked at as a rule, but I am intrigued by the thought process and to the implications for the game medium in relation to other more traditional media.
I'd say it works as a rule for games about as well as "show, don't tell" works for linear storytelling. It's a nice adage, but in truth any story that attempts never to tell is going to be long, complicated and inaccessible. I'm not sure such a story even exists - yeah okay, I guess there are stories with so little actual content than they can survive just indicating all of it, and some of those do work. My point is, I think it's a sweet ideal to "do, don't show", but in practice most games need their fair share of not only showing, but also telling, in order to make sense to its audience.
Can't watch the video right now, so maybe I got it all wrong... Just going by the idea of "do, don't show" that I've come across earlier.