What is Twilight thinking about? Probably about the infinity of our Universe, and how miniscule she is to even comprehend its size and know if there is someone out there looking into the sky like she is. Even if there is somebody out there, their silhouette would appear many years in the past to her, since light doesn’t travel fast enough to convey an instant picture of a distant stellar system to her eye.
Someone else would say - she’s thinking about nothing since she’s a cold soul-less AI image =).