Did you take chemistry or biochemistry in high school?? Wait, did you even finish high school??
Are you familiar with humidity in the air?? Humidity is basically water vapor.
The virus is airborne and your breath contains 5% water vapor. Average human breath contains 500 ml of air and we take about 12 breaths per minute while standing still. If I am standing in line in a store for 3 minutes, I have just released 36 breaths of 500 ml each which equals approximately 18 liters of air. So if 18 liters of air consists of 5% water vapor, that means I just released 900 ml of water vapor into the vicinity of where you are standing, which is potentially loaded with viral particles if I'm infected with Covid-19.
As the video shows most masks will NOT stop that water vapor from spreading.
Add points if the weather is really humid, because that increases water vapor coming out of your breath.
This might explain why we've seen an uptick in new cases here in Ontario last July and August