IIRC, Mr GZERO, for example, claims that the videos of breathing W/and W/O masks shows the spread (or lack of) of droplets/aerosols. I think it more correctly shows the variation in the index of refraction due to the temperature difference of exhaled air.
Surely the presence of “wetter” air makes an index difference, but I think the major difference is due to the temperature. Data for both exists,[1] but I leave it up to youse.
Of course, whatever, the point is correct.
bc …. as widowered, too busy collecting stuff to give to NCNAAPT and colleges.
[1] I’ve found (internet) and is in my computer’s storage.