I really enjoy that trend. Tech is a dry topic with typically uninspiring presenters.

I agree, I went to a conference the other weeks where the talks where extremely informative but after a day of presentations it becomes very hard to listen even if you're passionate about the topic.

I enjoy the more casual approach than the dry textbook approach, I don't have an academic background however and that may be the difference.

Crowds love that stuff though. When you're sitting there in person, you don't have the luxury of switching to a different tab for entertainment :)

I know you're joking, but there is a kernel of truth; crowds do like it. It's sad that people choosing to attend a talk about Angular.js don't find Angular.js interesting enough on it's own. They must have a rattle to amuse them.

I agree, that serves no purpose. It's just distracting. The "introductory joke" in a talk is sufficient to relax the audience.