According to this webpage on the Hong Kong Observatory, Hong Kong has not seen snow in the past twenty years, and since 1967, has seen snow on only four occasions. That sad truth could cause any non-traveler in this city to become insanely jealous of those that have traveled to places with snow.
I, myself, have been to Korea, Canada and the States (including Alaska [but it was just to catch another flight at the airport]). Fluffy, flimsy foam doesn't even come close to the clean, crystalline beauties that snowflakes are. Look at the pictures above and below. The foam is traveling upwards and sideways. Real snow would fall from the sky. Look at the guy in the picture below, with foam all over his face and head. The foam has adhered to his head. Real snow would melt. And are the people in the picture below indoors? Foam can't be served as real snow.
Sigh, it truly is sad that I probably won't see snow for another year since I went to Canada/USA eight years ago. But I found a digitally altered image depicting a snowy Hong Kong that made me smile a little (Click to enlarge. On the right is the Hong Kong harbour without snow for you to compare):
Using foam as a substitute does nothing but remind us people living near the equator that we. don't. get. snow. ...It shoves in our faces the fact that we can't have snowball fights, make snowmen, go skiing, go sledding, go snowboarding, make snow angels or uh... make igloos... or um... pee? Pee on the snow? ...I heard that's popular for some reason.
Foam-for-snow requires soap, and the power of wind to make it function and even that doesn't produce proper precipitation (prominent and priceless alliteration!). Foam gets in people's eyes and it stings. It gets in people's hair and clothes. The foam accumulated on the floor makes people's shoes and socks all wet and soapy. And the joy of having foam sprayed everywhere is a short-lived phenomenon, as Nature, surprisingly, is not bringing down craploads of it from the clouds.
As a concluding statement, and as I think it's rather playful: 'Foam' is 'phony' and 'sham' put together.