Why is mean forced around 100 in the settings?

[ClimGard]

I try to use the Cohens'd visualizer, but I can't put my actual means in the settings: I'm forced to center around the value of 100.
Is this normal? I don't understand how it works.

[Yingjie4Science]

I have a similar question, but for this post -- why did you set mean2 or u2 as 1, instead of 0, in your example?