I'm astonished that people are still arguing that Pax need more information about this.
It's simple, pull mask to put over your mouth. They don't need to know why the bag doesn't inflate they don't need to know how hard to pull the mask just follow the simple instructions. The only time you'd ever need to remember to pull the mask toward you would be if you were stood at the toilets and grabbed the nearest dangling mask.
Let's be honest, if your mask wasn't working for some bizarre and unlikely reason there is very little you will be able to do about it anyway.
What next, Pax needing to be briefed on what happens during a G/A, rejected T/O etc...