On a Prestige (business) ticket, you're seated in the first class seat, but get business meals/ground services.

The business seats on the plane have only economy services, and seem to be allocated to elite frequent fliers (I'm not sure exactly what the requirements are, though).

This allows KE to sell additional economy seats on a leisure-focused route. On a recent DPS-ICN flight, only nine of the twelve seats in the first class cabin were filled (so nine Prestige class passengers). At least one of these was a staff member.