The video demonstrates the difference between lighting normal thermite, which produces a cool glow, and a modified version that removes iron, resulting in an even more impressive reaction. The modified thermite is highlighted as particularly exciting, requiring viewers to stand far back due to its enhanced coolness.
Now let me show you why that was so cool. For reference, let's go ahead and light some normal thermite. This stuff leaves a really cool glow, especially if it's night time. If you thought the first one was cool, by removing the iron entirely, it gets a lot cooler. This is the one you stand really far back on.