This would work I'd the virus was contained in water droplets (the thing we are seeing in the image), but the problem is that the virus is completely independent from water and floats in the air.
Masks do almost nothing, because some amount of virus will get through and become airborne, quickly filling the entire room. Having a window of open in the room you are in is more effective than having everyone masked, and not being in the same room as an infected person is the most powerful prevention measure we have.
The fact that the medical establishment knows this and continues to push masks just shows that they don't care if the virus spreads - in fact they must hope that it does, because it makes them more money and power.