The thumbnails are too small making it hard to see the differences.
When comparing artificial light, we usually look at a few qualities of the light:
A soft light evenly lit a subject. A direct flash is hard, creating unpleasant and strong shadows. A soft light is large and it wraps around the subject, making shadow less visible. This is a good light to use for portrait unless you are going for some really dramatic lighting. For a light to be soft, it needs to be as big as possible relative to the subject.
If you have a light that is 8 x 8 feet, if you put your model's face close to it, the face will be lit evenly from all directions, because the light is so huge. This almost eliminates all shadow and is sometimes seen used in cosmetic adverts. If you lit the same face with a flash that is about the size of a biscuit, the model's face will be lit from a single direction, creating awful shadows and highlights.
Secondly, the intensity of the light. Sometimes when the light shines directly on the subject, it creates what we call hot spots. Look at the tip of a model's nose and you will usually see a dot of light, making it looks like her face is oily. When the light is strong and linear, you will be creating a lot of hot spots. This can appear on the model's nose, forehead, cheek bone, lips, chin etc. The face will appear as if it was smudged in oil, unnatural and utterly flat.
This happens when the light is very directional. If you have light that travels in all directions, it is more diffused, and this will reduce hot spots. People use all sorts of techniques to make light travel in a diffused manner. Bouncing off the ceiling, shooting through some fabric, reflecting off an umbrella's inside etc are all good ways to make light travel less linear. This create pleasant lighting for portraits.
Lastly you want the light to be even. You do not want it to reduce in intensity rapidly. This will result in, for example, brightly lit nose and poorly lit cheek. Or when taking group photos, you may end up with a photo where a person face is well lit while the other falls much darker. A large and diffused light source helps.
Generally speaking, a soft light that casts itself across the subject face without hot spots or strong highlights is a good light source for portraits.
However there are also times where you want to use harsh light to make the result more dramatic.
The light modifiers are only there to help control the type of light that the photographer wants.