Because I've been looking for the 2nd Army's patch and I can't find it ANYWHERE.
Wasn't easy to find, but I did. The French 2nd Army used a gallic rooster superimposed on the French flag for their patch.
I haven't been able to find any photographic evidence that anyone actually wore this patch in combat. Most of the photos I've seen of Free French soldiers has them wearing either nothing or the French flag.