I went to a (very) posh restaurant years ago, where a vintage plate (and cutlery) were chosen by the chef to create a different ambience around every dish.
My first thought was that the whole idea was a bit naff, and that he'd been to a jumble sale and bought a whole load of cheap crockery to save money.
But - when I saw, and tasted, the food, was my mind changed!
Sounds like Jamie might be trying to create a similar sort of atmosphere around his grub.
I'm not entirely certain that's possible in a chain restaurant, myself.
However, if the food is delicious, that's the only thing which matters in the end. Shabby chic is a hard thing to pull off, and the decor looks ok in the picture.