I think it's more of a tongue-in-cheek self reference. "We've spent a lot of time observing what people are doing on Twitter, and we see them taking screenshots

I think it's more of a tongue-in-cheek self reference. "We've spent a lot of time observing what people are doing on Twitter, and we see them taking screenshots of text and tweeting it." The spellcheck underline at the end was probably not just carelessness, though I don't follow the whims of tech royalty very carefully. The fact that I had to tab back and forth to type up the quote drives his point home for me.