The sad thing is that most people will look at that video and think 'oh that seems hard' or 'that style isn't for me'..... that's pure naivety through and through. If you're going to day trade, using the order flow on the DOM is the only way to trade if you're planning on trading for a living. If you go down on the floor of the various exchanges, you'll see all the locals trading like that. If you go onto the trading floor of any half decent prop firm, it's pretty much how everyone trades. All you see is a sea of DOM'S. If you don't accept that as a day trader you might as well quit and save yourself a lot of money and pain.
When I see threads like 'Is Anyone Make Money From Day Trading' - The answer is, if you're retail who's hell bent thinking they can apply technical analysis to day trading then no, you're not making a penny, or haven't made any consistent money for a few years. If you're going to go down the the road of applying technical analysis to day trading then you're literally just going to be handing all your money to the professionals and those who understand day trading is about the DOM. Ignore this advice at your own risk.
Here are some pictures of trading floors just from google image, you'll see DOM'S are what traders are starring at for their trades....
Big screens with the doms up at the CME exchange