This is a training aid for mastering the Kumbhaka Hold, as described in Yantra Yoga: the Tibetan Yoga of Movement by Chögyal Namkhai Norbu, p.140.
The Kumbhaka Hold is a form of Box Breathing. It's an ancient technique for activating the parasympathetic nervous system, calming the fabricating mind.
The top-left corner shows the current training level, like 4 10 6. That means a 4-count inhale, a 10-count hold with air, and a 6-count exhale and hold without air.
The line moving up represents inhalation and a hold with air.
The line moving down represents exhalation and a hold without air.
Gently follow the line and breathe with relaxation.
When the current level is easy and comfortable, advance to the next level. The full training program consists of 398 levels, all the way up to 16 64 32.
You can use the top-left controls or the keyboard left/right arrow buttons to change level. The space bar and down arrow reset to the start of a fresh inhalation. Click to zoom in or out.
Please relax and enjoy!