ShiroKuro Nope, I never do that. 😆 I look at the key signature, note the number of flats or sharps… sometimes (but not always) I will play them (i.e., I literally play F#, C#, G# first with the RH and then with the LH), esp. if I was just practicing a piece in a different key signature and I want to reset my brain. And then I start in on the piece. That’s it. Depending on the music, and on what kinds of practice strategies I’m employing, I might look through the music to find the most difficult section and start there (I used to do this religiously, but I’ve mellowed in recent years and I tend to just start at the beginning these days). But even this is not looking through the score to understand the structure of the piece. Although I do learn the structure as I read-play through it…
So I'm thinking about all this. One thought is, a thing I learned about myself is that every strength is a weakness, and every weakness is a potential strength. As a simplistic example, the by ear player trying to learn to read music while looking at a score of music he already knows will have his ear take over preventing an engagement with the notes on the page. These days I'm a relatively strong reader. The notes on the page "dictate" what I play next and I don't have to be aware of anything for my fingers to go to the right place (though knowledge will help, esp. if the style is unfamiliar). If you never have to remember or know what's coming next, because the page will tell you, why would you gain that facility or even think of acquiring it?
In memorizing music maybe we have two aspects. One is the details of the moment - the small sections that the pianist on YT focused on. The other is that you have to play the whole piece and pieces often have distinct sections. You have to keep track of the whole thing. This is where I think the device of "remember the first note of a section" comes in.
For this 2nd macro-view for setting up sections, I think awareness of basic musical structure can help. Yes, you might memorize that "this section starts on A" - but will you still remember 6 months or a year later? But if the piece is in D major, and the section has modulated to A major (as music often does) then you can also predict the probability of that A to help you. My feeling is that patterns play a role for helping to memorize. Also combining the macro and micro view.
This may be dumb: I noticed that grocery stores always seem to have the same layout, in that the fresh produce is always on the right near the door. If I see something yellow in that area it's likely to be bananas or lemons, and unlikely to be a tin of cornstarch or a dustpan. I'll zero in on details like comparing price, checking ingredients, but I also have a macro view of the store. (This is a terrible example.)
Because I've had to address different things, I've learned to switch up how I do things depending on the aim. Is everything done in sight reading also the right process for memorizing? Might new memorizing processes give new skills to reading music in unfamiliar styles?