I'd also add, photographing slides is not the same as writing things down. (especially if you're photographing every slide, to the degree where you're paying little attention to the speaker)
> the same as writing things down
Ah, I could go down this rabbit hole but (after a lot of trial and error), I have come to a (reasonably working) method. It's not enough to write down what you hear/see . I find it so much better to link what you write down to something you already know. That way, things tend to stick longer. Otherwise the notes are just that -- a random collection of things you have written down. No idea if they will ever surface in your memory.
I think that was the point of the article - actively listen and identify only 3 main points to write down.