credit cards appear on the Mac with the icon according to the type of card (Visa, Master, ...). but in the app for iOS icons that appear they are the standard, not allowing identify according to the icon.
Thanks for writing to us about this. That is the current state of things, yes, and unfortunately at the moment there isn't a way to customize or change that. The cards are actually identified by an icon in the detail view depending on the brand (if you will) of card, but not in the list view.
As we work toward more consistency across all of the platforms we support it is likely you'll see more consistency here, but I don't have further details or a timeline to share at this point.