Mayo
Here is the Mayo Clinic's take:
Mindfulness is a type of meditation in which you focus on being intensely aware of what you're sensing and feeling in the moment, without interpretation or judgment. Practicing mindfulness involves breathing methods, guided imagery, and other practices to relax the body and mind and help reduce stress.
Spending too much time planning, problem-solving, daydreaming, or thinking negative or random thoughts can be draining. It can also make you more likely to experience stress, anxiety and symptoms of depression. Practicing mindfulness exercises can help you direct your attention away from this kind of thinking and engage with the world around you.
https://www.mayoclinic.org/healthy-lifestyle/consumer-health/in-depth/mindfulness-exercises/art-20046356
In my experience, traditional meditation, say with a mantra, is to empty one's mind of all thought. "Empty your mind of everything." When I meditate, it is an attempt at awareness. Every sound, smell taste, sensation. I mainly practice it if I am waiting for something, like waiting at the dentists, or the DMV, or in a line at the store. Instead of getting pissed off at my impatience, I count the people, I notice what they are wearing, I look for exits, I count the lights, the chairs, look at everything on the last minute buy rack...
Or yes, as you say, look at myself and my thoughts from the outside.