One 40x32 inch double diffused softbox, fabric at 18 inches.

Note the reflections on dish in front of eggs are reflections, not shadows. The shadows are soft and vague (under dish, for example). The large light source wraps light around the eggs and under the dish. The way it does that is because the 40 inch softbox (or umbrella) is 18 inches from the 7 inch dish (big and close), so light comes to the egg from the left and from the right, and from every which way, which fills its own shadow. This is how large light sources work, by being close in order to become relatively large. And large is what makes soft. The softness smooths skin, which is good for portraits.

There are mirror reflections of these eggs on the dish (shiny dish), but notice the soft light wrap also lightens the dark canyon between the eggs. This is a day and night difference, in several respects.

THIS Flash Basics page specifically details the definitions of Soft Light.