I really appreciate how you’ve used the same environment for both images. This helps communicate the difference that different intensities in light have on your objects.
In your first photograph the shadows are much sharper and stronger. In your second image, the shadows are much softer and therefore create a less moody tone.
Generally speaking diffused light looks better on people. Hard light often causes parts of your exposure to “burn out” (AKA blow out). You can even see this in your second image (soft lighting) on your tallest object’s head (near the top). Your exposure is “clipping” slightly causing you to loose the digital information in that area.
The same problem is found in your hard lighting photograph on the floor between your tallest and second tallest object. If you haven’t already, please read our blog post on this issue here:
It’s very important that you read that article as it will help you understand dynamic range much better.
You should also be watching film and exploring photographs based on their shadows. This will help you identify where the creator of the image wanted the light to be positioned for their composition. You can tell by how the shadows fall on the subjects or on the environment.
I can tell you’ve used a ¾ backlight based on where the shadows are falling.