Are the hooks set up like little white artificial flies?
First, herring are ocean fish that come into inlets to spawn in the spring. Smelt do the same.

Herring rigs are designed to be used during the spawning run. You jig them up and down. Usually a weight gets snapped to the bottom swivel and the top swivel is for your leader.
The herring will strike at the artificial flies,
usually as they flutter in the way back down after you jigged them up.
The herring have small mouths and are less than 16 inches long, more likely about 12 inches. They only eat small stuff so small flies are used.
I have seen people jig them and get a fish on each hook when the run was heavy.
Herring and smelt fishing are best at night when they come near the surface to feed.
I suppose you could fish it for smelt, they are not much different in how they feed.
It is a jig type rig and meant to be fished up and down so I suppose it might work OK as an ice fishing rig.

Smelt under the ice, small trout or perch? Small hooks can catch big fish too.

The only thoughts I am having are if it is not cheaper to just buy hooks and rig your own, and that ganged hooks are illegal in most of the fishing around here.