Indicates a contemplative mood or disconnect from surroundings, not just physically seeing. He would often stare out the garden, oblivious to the chaos around him.
Pro Tip 2/3
Quiet Observation
Implies a silent and lengthy observation, showing interest or being deep in thought. During the tour, she couldn't help but stare out the historic paintings.
Pro Tip 3/3
Not Rude
Staring out is typically considered less rude than staring directly at a person. She apologized after realizing her stare out the window may have been misinterpreted.