I own both the Air 2 and Air 2S just because I wanted the 1-inch camera upgrade. Since there are plenty of reviews and comparison videos on YT, I don’t think of any of them saw this minor visual difference.
The controller battery indicators light up differently. White on the Air 2 controller, Green on the Air 2S controller. Obviously both can work with each other once firmware has been updated. Also on the Air 2S controller the RTH button now has a pause icon.
Again no functional differences, just visual. (Air 2 controller on left, Air 2S on right. and yes I used a wrap on the Air 2, undecided if I will wrap the Air 2S)