Is guest content or a professional shoot the better base?

The shoot carries the feed, because the light and the dish have to be the house's. Guest photos belong in stories when they are recent and the dish is still on the menu, and they do not belong as the only image of a dish you then advertise. Ask permission and check that the dish in that photo is served this week before you republish it. The profile leans only on dark guest photos and, when it is time to advertise, there is not one clean frame of the dish. The month's feed comes from the shoot, and guest photos go into stories with credit and a date, never as a substitute for the bank.