Is to say "hush" different from saying "be quiet?"

I know summarizing is an important skill, but what's the ideal length of summarization?

There is no ideal length for summarization, it depends on the task and context! However, generally, try to keep things short, simple, and easy to understand. For example, try to take the main ideas of something and shorten it into one, easy-to-read bullet point that shouldn't be longer than a couple of lines. The point of summarization is to make it easier to categorize, remember, and analyze information! Ex: I was asked to summarize the book into one short paragraph. Ex: Can you summarize the meeting notes into a few short points?

What's "corresponding to" mean here? Is this commonly used?

Here "corresponding to" means "matching," "agrees with," or "equivalent." So the number in the tab needs to <match>, or be the same as, the one on the column. It is common to use "corresponding" like this! Especially in technical settings or when dealing with documents and forms. Ex: Make sure your name on the form corresponds with the name on your ID. Ex: You need to find the taxi corresponding to the number plate on the app. Ex: This battery won't correspond with the required voltage.

What's "stare at" mean? Is it same as "glance?"

To "stare at" is similar to a "glance," but not quite the same. A "glance" means a quick look, and then you overt your eyes. Whereas to "stare at" means to look at someone or something for a prolonged amount of time or to not look away for a while, and the "at" indicates that one's staring is directed specifically at something. Ex: I went out in my halloween costume, and everyone stared at me. Ex: She glanced in my direction as I walked past her.

What does "your body" mean here?

"Your body" seems to be emphasizing the outfit that she is wearing as if to say that it's a part of her, that the ridiculous outfit looks great on her. There isn't much context to go by in this trailer since the previous scene might not be tied with this scene. However, they do show her trying on multiple outfits as if to find the perfect outfit.

Why does the speaker say "in order to"? I think just saying "to" is more simple.

You are right! In most cases, "in order to" can be simplified to just "to" without changing the meaning of the sentence. However, many choose to use "in order to" due to personal preference and the fact that it adds a slight tone of formality. However, you can choose to use it or not. Ex: I need to get a 90% on the test in order to pass my course. Ex: I need to get a 90% on the test to pass my course.