My personal experience of a few dogs and a lot more cats. Cats just aren't as hypnotized by the Plate. Instead of looking slavishly at the Plate and imagining wonderful, wonderful FOOD! on it, they'll jump on some piece of furniture overlooking the table to see what's inside. Then, they'll quickly determine if it interests them or not. If it does, then they'll jump on the master's lap and from then on their whole head will be tugged by their nose, which will be in unerringly attracted by the food.
The plate, itself, though, is absolutely devoid of interest. Contrarily to the dog who can be fooled with an empty plate. It's a Plate, it must have FOOD!, thinks the dog.