The bands
A score is grouped into a band so it reads at a glance: the higher bands mean today looks like your own better recent days, the lower ones mean it looks like your own harder ones.
Why your band moved
The card names the factor that moved furthest since your own baseline, chosen from a fixed set of sentences. Two members with the same inputs read the same sentence, because nothing about it is written on the fly.
What a band is not
A band is not a verdict, not a grade, and not a statement about your health. It is your own recent figures, grouped.
Peers who can see your progress see the band and never the figures behind it.