Possible secrets if Pokemon FR/LG are inserted into the DS for HG/SS??

[Naraku_Diabolos]

http://www.pokemon.co.jp/special/hgss/story/

Underneath the picture of Japanese text, there is a gold bar to select. When clicked, the bar blows up a picture with Giovanni and talks about the insertion of FireRed/LeafGreen. Is there some hidden bonuses if those two games are inserted??