I don't know if all dogs do this, but Loki will stare very intently at me.
If he stares at me at close range, it means he wants to either play or go outside. Usually, I take him outside just in case he does have to pee, because I think it's useful for a dog to be able to communicate the fact that it needs to go pee. But I've definitely noticed that Loki's testing me to see if he can get me to just take him outside for fun rather than for a pee. Sometimes he gets away with having his regular walks earlier than usual; sometimes I say, but I just took you out! No play!
But what does it mean if he's staring at me from a distance? He'll be sitting by the sliding door to the balcony, while I'm at my computer. From time to time, I glance over at him and there he is staring intently at me. It's a little bit unsettling to know that he hasn't been looking outside at the world at all, he's been just staring at me for who knows how long!