Style Reference sliders Visual Intensity vs Strength ?

In the wonderful Style Reference section there are two sliders: for Visual Intensity and Strength. The difference betwee these two is unclear to me, also because the terms of both sliders seem quite the same to me.

Since it's impossible to let Firefly create the exact same image with just one single parameter altered, I can't tweak the sliders to test and understand the difference. It must be something very subtle.

It gets even funnier when you read the information in the popup about the Strength slider: "Control the fine-tuning with just a single button" (or something similar in your language). Well, then why are there two sliders ? 

Who can shed some light on this ?