No, PokerStars Can't See Your Screen\n\n Another thing that is mentioned in the blog, is that PokerStars are unable to see what is on your screen.

Over the years, the Twitch poker ecosystem has expanded. Many of the leading online poker rooms have live-streamed their own events and employed their own brand ambassadors to develop a following on Twitch. The likes of PokerStars, 888poker and GGPoker are all still heavily active on Twitch today.