To naively summarize, it’s kind of like counting sheep but instead of sheep you’re counting breaths. You take the time to notice things that you don’t normally notice. Your chest rising and falling with each breath. What do you smell. Notice how much force you exert on your seat as you sit, etc etc.
Ironically, if you are bored then meditation is the absolute best way to find something to do. 10 minutes easily feels like 40 minutes. Your brain will naturally drift and start prioritizing the most important things you need to work on. Maybe you’ve been procrastinating and all of a sudden you have an urge to go deal with that stuff.
After meditating you have a good sense of what you need to do next, which unfortunately can then make time speed up as you get busy.
The best way I can describe my experience in this state, that I’m able to reach from time to time, is like being in between frames of film - I’m in the dark part after one frame, not reaching the next, and everything is just still.
Controlled but yet completely uncontrolled and a few minutes feels much much longer, but nothing makes me want to leave.
After the first time it happened I ran out to my wife and yelled “holy expletive! Now I get what this thing is about!”.
It really made a change for me and it makes my brain/mind feel about the same as it does after a run. Fresh.