This question refers to the text The Flight from Conversation by Sherry Turkle .
Answer:
With this phrase Turkle means that because of technology, we are all alone since every time we share less with people in a physical way and we do it more in a virtual way. But since it's something we all do, she says we're in this together. That's why she uses the phrase "alone together."
Explanation:
These words have a great influence on what the whole article is, since she wants to emphasize that really the vast majority of people are in this situation.
People just want to pay attention to what interests them, ignoring everything that doesn't.
This means that we all get more and more into technology and ignore the people around us, just to communicate virtually.
We are alone, but together at the same time because we remain connected even though we are immersed in technology.
