The portrait, hence, will have softer light and excellent catch light effect.
Now, if the same diffuser or soft box will be used to capture images of an M&M chocolate, the same quality of soft light will be achieved. In addition, the setup will also sharpen the image, enhance the quality of the shadows or even minimize it and increase the depth of the field. An ordinary flash will only provide illumination on the subject and not the background that is why shadows emerge in the process. Using multiple flashes could solve this problem but so will a diffused flash.
If the photographer wants a sharper contrast, the diffuser can also achieve what multiple flashes would in this situation. A single M&M candy is small and rounded, hence, this type of flash tools are useful. It is important to remember that light can reveal the shape of the object being captured and being able to control it through the diffuser or the soft box would effectively achieve this