I liked the fact that this talk was quite different than the others. Telling a good story. However, the speaker was a bit nervous, and the long pauses in the speech were distracting, interrupting the flow. I would add just a few more technical details, and try to relax a bit more. It will make be a much more inspiring and entertaining speech.
I got lost when the speaker moved from docker to dokku and in geneal in the very last part of the presentation. I would work on that transition, because to me it was not clear... But for all the rest, very goot talk.
Really good presentation! The right mix of wow is this cool and actual facts. And telling me all the things i want to know: Why should I care? How does it work? Where to go from here? If i have one point you could improve, that would be to be more enthusiastic about how cool docker is.