They aren't. Barge-boards are one thing, and Sidepod Shields are another:
Bargeboards are the curvy bit immediately in front of the sidepod, and they're very low. That's the zig-zag shaped triangle bits on last year's cars, or the unpainted bit on the launch Ferrari F60.
Sidepod shields are something that sticks out, usually on the side of the sidepod and slightly ahead. The Ferrari's mirror-thingies are a sidepod shield - or a "mirror-shield", as this specific interpretation was dubbed. The Toyota also has a sidepod shield.