DS games know their hardware?

Reports are coming in that some DS games might know whether they are being played on a DS Lite as seen in the above video. When starting Mario Kart DS on the original DS, notice Mario's "Yahoo!" as compared with his DS Lite's "Here we go!"

However, another video suggests that this may be a game setting such as percentage of completion, etc. Do any readers or super Nintendo nerds want to shed light on the discrepancy?