Thanks for actually measuring, that's the most useful reply I've had.
You're right about the outline. I checked and the thin green line vanishes long before the numbers do.
But I don't think the box is why the new one holds up. The panel is nearly the same dark on both cards. What changed is behind it: the old one sits on a dark background, the new one sits on a bright road. That gap is doing the work.
Which means it breaks on dark art. A lot of the roster is night scenes and dark animals, and those would look fine up close and disappear from across the room.
So the panel probably needs to shift with the art instead of being one fixed color - worth a test but thanks for helping me see it!