Learn English – the meaning of the phrase “what it is they do”

Here's the quote with a bit more context:

"We're going to double down on secrecy on products," Cook said, but on other things, "we will be the most transparent company in the world," - like social good and supplier practices.

Double down is originally a blackjack term to play for double or nothing.

It is used more generally to mean make a calculated gamble to double your commitment, to concentrate or focus on something.

But it seems like use is changing, and it's simply means you will try twice as hard (as there's always some inherent risk in everything).

Cook is simply saying Apple are going to be more serious and committed about product secrecy.

The linked question asks about:

Palin is notorious for doubling-down on perceived missteps, typically blaming a biased media for not telling the whole story.

This is similar; Sarah Palin concentrates and pays extra attention when people claim she makes mistakes, usually trying to deflect blame to the media.

The phrase “wouldn't blink twice” sounds to me like a conflation of a “wouldn't blink” idiom with a “wouldn't think twice” idiom.

“Wouldn't blink”, in forms like “wouldn't blink an eye” and “wouldn't bat an eye/eyelash/eyelid” connote not reacting or responding, ie, failing to show surprise.

“Wouldn't think twice” means not having to give something a second thought; ie, not having to reconsider something, because it is so obvious or clear in the first place.

Edit: Following on from Sven Yargs' comment, some Google ngrams results may be of interest. First, a few caveats:

_{• Google ngrams records the 't parts of contractions wouldn't and didn't as separate elements. A search for ' t is satisfied by wouldn't, couldn't, shouldn't, didn't, don't, etc.
• Near the end of Google's ngrams info page, it says “we only consider ngrams that occur in at least 40 books”.
• Books linked below the graph mentioned below include a few dozen results for ' t blink twice even though a page label says there was only one result.}

With those caveats understood, the general trend according to the Google ngrams graph for ' t blink,' t think twice,' t blink twice, is that overall frequency of ' t blink is about the same as that of ' t think twice; both forms have been occurring since the early 1800's; each occurs several thousand times as frequently as ' t blink twice. That is, ' t blink twice negative contractions are significantly uncommon (a few dozen occurrences, most within the past 25 years) compared to ' t blink or ' t think twice negative contractions.