Tooltip on profile incorrect

If you go to your profile in the client, on the overview tab.

Hover over the mask (Dynamic Background) it says : "Your friends will see your most-played champion (from the last 20 games) when they view your profile."

I do not believe this is the case, shouldn't it read something like ""Your friends will see your highest mastery champion when they view your profile as your background." ??

Correct me if I'm wrong, but It usually only shows my highest mastery, not the champion I've been playing the most in the past 20 games