He’s highlighting the benefits of a language over another language. Imagine if you went to the Julia website and as a summary they gave 20 snippets of code to illustrate what Julia is. No they don’t do that, they give a qualitative description of the language, which is exactly what you would want if you have interest in the language… So your comment doesn’t make any sense. Why would he have to show code when making a statement like “ Julia is fast” or “ Julia is dynamic” when these are just facts about the Julia language that you could literally read off the front page of their website.