First lets understand that anything inside you bodies electrical system aka aura causes reactions. The smallest muscles react the most and the shoulder if the arm is positioned correctly will hold on the power of a single small muscle.
Another way to put this, when people have cancer and necrosis they usually complain about fatique. The earliest signal is the muscle behind the eye, can't focus on print or computer moniter etc. But the shoulder and ankle muscles also weaken dramatically just from necrosis inside the body.
Now she goes through all the tests and Qs which for simple muscle testing are not needed. If you want to see a strong weak reaction hold a bottle of bleach or a container with Vitamin D near your thymus.
Your reaction should be strong enough that the person testing you can send your arm down by a super light touch.
Remove the bleach and now test your supplements one after another near your thymus. You can also test logical groups. For instance TMG, 5HTP and SAMe at the same time. If indifferent the arm will go down with the same pressure as if you are not holding anything. If its stronger than that you can remove one item at a time to find the one you react most to. Once you know that you can begin to understand where your issues are at.
Asking Qs like she does on the video turns it into Quantum Mechanics and that's another step. Right now simply entering a product into your aura is all you want to test.