Math, it's all about math.
CNC machining is a collection of different skill sets more so if you are a one man operation. You have to understand manual machining, materials, methods. You have to understand the programming environment typically Mastercam & Solidworks. I use OneCNC as it's more of a shop floor hands on modeling and CAM software. You have to understand the work envelope of the machine your working with. The tool clearances in the video are tight, if you don't have your act together, a tool crash can cost you a whole pile of money. Finally you have to understand the tooling, specifically the types of inserts & coatings used.
Tooling is a sore spot for me, these tool salesmen come around pushing their inserts and magic coating end mills and what not and give you an off the cuff recommended feed & speed and they often have no clue whatsoever, and even try to sell you inserts that aren't for your material. You need to sit down and read the data sheets on every tool that you plan to use, confirm the material application, do the math based on the formulas for the feed & speed, calculate tool life, MMR etc.
That demo video is as much about the machine as it is about the tooling choice & application for the material & the programmers skill. I enjoy machine razzle-dazzle and that's no quick & dirty demo thrown together in haste.