For anyone else who was similarly confused as to what this was even about without watching the video: Pandas is a Python data analysis toolkit, and Vincent is a Python library that makes it easy to build D3-based visualizations from Python.
Just FYI, it looks like an interaction between SublimeVideo and HTTPS Everywhere appears to prevent the video from playing -- unchecking SublimeVideo in the HTTPS Everywhere options seems to fix the problem.
I don't seem to have an issue.
Odd. I can uncheck/check the SublimeVideo option and reload the page and it will either show the video as a static image or give me a play button. I'm on Mac Chrome 29.0.1547.76. Maybe my corporate firewall is messing with it somehow.