Great talk and very well rehearsed!
It might be helpful to spend few more minutes on explaining The Magic behind steps - especially mink steps. Maybe slow down when showing the code and let audience scan through the example code.
To sum up: the marketing part - very well done(!), the tech part - needs few tweaks.
As someone that's never used it before, I felt you skipped over the code examples a little fast. I appreciate you were just giving an overview, but some of it seemed to happen by magic.
Fot instance, the ".conferences" test. Did it automatically know to look for an element with a class, and just look for the string within it?
Apart from that, great talk :)
Good talk, shame I missed the beginning. Might wanna zoom some of the terminal stuff and add some borders.