AYou can find it at country kitchen.....also know as CK:-)
The pic is very tiny, but it looks like inedible plastic Disco Dust to me.
As long as you're CERTAIN that the snowflakes will be removed and not eaten, it's OK to use. It would be important to emphasize to the client that the decoration is covered in plastic and cannot be served.
You can get a nice, completely edible shine by using fine grain sugar and FDA approved edible luster dust and/or edible cake sparkles [made with gum arabic].
AGreat point maybenot! Didnt even think to mention that very important detail:-)