This is definitely a theory presentation, though it does end with some applications to hyperparameter transfer when scaling model size. But if your main experience with ML is building models and applications, I'm not surprised it looks unfamiliar.

That being said, though, give it a chance if you're interested. Some parts of the outline didn't look familiar to me either, but the video is well-made and stops to explain most of the background knowledge. And you can always gloss over the bits you don't understand.