I've definitely seen the two-kitchen setup at the houses of some more well-to-do family friends. The kind of cooking done there will usually be only the final

I've definitely seen the two-kitchen setup at the houses of some more well-to-do family friends. The kind of cooking done there will usually be only the final part of the meal, e.g., searing the steaks after the vegetables have been made in the work kitchen, or assembling the sushi after the rice has been made. Cocktails would also potentially be mixed here (unless they have a separate bar area for that). The guests would sit around with their drinks and chat to the host whilst they create the final part of the meal, or perhaps a starter, and serve it freshly prepared. It's an extravagance, to be sure, but it allows wealthy hosts to show off their cooking skills in front of guests.