Why would he mention the word "sleep" in this context? Is it a metaphor?
Native speaker’s answer
Rebecca
So, I think there are two meanings to this. First, there is a common belief that people love to "waste" time on technology, like using cell phones until late at night which prevents us from sleeping. Tim Cook is maybe referring to that when he says that "it's technology that helps you sleep, not keeps you up" to state that the function of the technology is going to be the opposite of what it is doing right now. Secondly, "to be kept up" is often a way to state that one's worries make it difficult to sleep at night. Indeed, privacy concerns can cause people to worry. Thus, Tim Cook's statement might mean one or both of these meanings. Instead of stimulating us to stay up late at night (either due to time-wasting technology or privacy worries), the technology is intended to make us feel secure and safe.
