I don't follow your explanation so I will start over.
First, you will learn how the toy HTML looks behind the scenes. Then, eventually, as you become comfortable with how this looks, you will progress to more difficult stuff.
It does not seem like a condition, exactly, and yet it is. So long as the toy HTML looks like a confusing jumble of characters, you're not ready for more difficult stuff. But when you feel comfortable with the code, as you kind of grow into it, you will move on to a new, slightly more difficult phase, of training.
That is my understanding with regards to the grammar, but I don't understand computer/internet code and HTML. You don't show enough of the tutorial for me to be able to see the entire pattern of instruction. Thus, I can't be completely sure I understand the process. However, I feel confident regarding the grammar. It is trying to show that you will grow into more difficult information, that more difficult information will be presented when you are ready. First the easy stuff, then when you are ready they present the more difficult. It's not as harsh as a condition.
I found the quote in the YouTube and transcribed the entire sentence below for a clearer understanding of the speaker's intention:
The focus of this lesson will be learning to navigate HTML to arrive
at the content we may be interested in retrieving. In doing so, we
will use a simple toy model of HTML as we become comfortable with how
the code looks behind the scenes, and see that we can picture a
tree-like structure of HTML to easily interpret the task of HTML
To understand that sentence, we have to understand the instruction style of the tutorial. The instruction style is to present a very simple piece of HTML coding, also known as toy HTML. He does this to make the student feel comfortable or familiar with coding. The word "as" does not really mean much the way he uses it.
On the other hand, if the interpretation of "as" could be that, A is a
way to achieve B, the whole sentence makes more sense.
No, A is not a way to achieve B in this case. Perhaps it might be said that B is a way of achieving A.
Let's look at the sentence again:
in doing so, we will use a simple toy model of HTML as we become
comfortable with how the code looks behind the scenes, and ...
Let's get rid of the sentence fragments before and after the parts under discussion so that our sentence looks thus:
We will use a simple toy model of HTML as we become comfortable with
how the code looks behind the scenes.
That could be rearranged to say:
As we become comfortable with how the code looks behind the scenes, we
will use a simple toy model of HTML.
Becoming comfortable, feeling familiar, with the coding behind the scenes is the foundation to learning more. He will not introduce more difficult material until you feel comfortable. As you become comfortable, he will introduce more. Thus "as" is interpreted to indicate the conditions of process, if that makes sense.
How about this one?
in doing so, we will become comfortable with how the code looks behind
the scenes, and ... as we use a simple toy model of HTML
I think you got it! If I correctly understand your meaning, you mean the same as I do.