This place has been around for 20-30 years, and they make most of the Vietnamese packaged sweets that you see in most Asian grocery stores.
The steamed rice cake (the one that comes in big white triangles) are their bread and butter, and sometimes they'll be packaging and pressing them outside in the store. They also have other sweets, like the green mung bean ones, the 9 flowers in white/pink/green, and cassava cake.
It seems like they mainly do the production in this facility, with a few snacks for sale at the counter, but it's a great experience to check it out, especially if you grew up snacking on those delicious Vietnamese sweets!