Staring at a dog can be fun, particularly when trying to guess their breed before asking the dog's parent whether you can pet their dog. However, you should be cautious about how you look at a dog.
Dogs interpret prolonged eye contact differently, depending on their temperament. Some dogs may become worried if someone is staring at them, especially if the dog is distrustful of people.
It is best to maintain your composure around unfamiliar dogs because they can interpret a stranger's stare as a challenge, a threat, or something that should make them feel uneasy. They might even worry that you're attempting to rob them of a resource like a toy.
A dog struggling with human reactivity might react to prolonged stares by barking, snapping, or biting to end the uncomfortable interaction. So, it is wise to avoid doing it.
You should also avoid eye contact if a strange dog appears to be staring at you, especially if they are rigid in their stance and unblinking. Instead, move aside to give the dog some room, as they are obviously uncomfortable with your presence.
If you are a dog parent, you may notice that your dog stares at you often, and that's fine. Dogs stare at their parents for different reasons, including to know them better and for signs that something interesting, like lunch or a walk, is about to happen.