The full 25 minute video is online. People who are quite familiar with Nimoy will have heard answers to the first few questions before but Williams does manage to dig a bit deeper and cover Nimoy's photography, time in the US military and what it means to be an artist.
Until now, I was only familiar with Pharrell from his work with Daft Punk but, chances are, you've heard his work without knowing his name. He has collaborated with dozens of chart-topping artists as a producer through his music label, Star Trak Entertainment.
A quick Google search showed me that Pharrell is often seen promoting his label and Star Trek fandom by throwing up the Vulcan salute.