[I see from the videos that this is a special interest of yours, so I won’t hesitate to write about it at greater length.]
In my opi...n, you can easily understand that last word (after ‘In my opi....’) without needing to focus on all the letters or vocalizing them. That’s because you’re familiar with the word ‘opinion’ — have seen it thousands of times — and are used to seeing ‘In my opinion’ in discussions like this one.
Let me emphasize again, though, that I agree with you that phonics can help with unfamiliar words, and that it may be the best foundation for teaching beginners to read (or, at least, it should be introduced at some point in the process and play a big role). Obviously it’s helpful, when you encounter unfamiliar words, to have rules for figuring out how they are pronounced — or probably pronounced — and what the various roots, prefixes, suffixes mean.
After you’ve figured out a particular word, though, and seen it hundreds or thousands of times, you should be able to take it in at a glance, without sounding out every individual letter. Fast readers do that, slowing down occasionally to “decipher” an unfamiliar one, but most of the time zipping along taking in words and phrases at a glance.
I’ll just tell you as frankly as I can...
1) The brain is an extremely ingenious machine, and does whatever tricks it takes in any given instant to get the best results. No one can be sure what is going on at any given time.
2) However I am confident from studying books by Rudolf Flesch, Engelmann, Blumenfeld, and all the others that I have reviewed on Amazon, plus my own intuitive analysis, that Whole Word is mostly nonsense. And as a tactical matter, I simply decided to be wholly against it. The problem is that so many people have picked up bits and pieces of propaganda from the Education Establishment. So now it’s like cleaning up a nuclear waste site.
3) Here is a wonderfully stark summation by phonics guru Don Potter (on my site under #42):
“The situation across the nation is dramatically worse that anyone can possibly imagine. When I ask the teachers why they teach sight-words, they inevitably tell me because their students are going to be assessed on them. They are totally unaware that sight-words are positively harmful. They consider sight-words part of a good reading program that includes some phonics, not realizing that sight-words create a reflex that interferes with phonics instruction. Sight-words are an obstacle to reading, not an aid.”
4) Flesch explained the whole thing in 1955. I can’t see that he got a word wrong.