A nice clean backside, if you ask me.
One other notable design change implemented on the TH-668 was the elimination of the easel (kick) stand that was on the earlier TH-669. The design team must have decided it was not a feature that users demanded, and were probably doing what they could to reduce the cost of the product. Sure enough, I suspect most people would just stand the radio on its bottom edge, even if the stand was present. These stands may work fairly well on the shirt-pocket radios that followed, but the similar ones used on the longer horizontal radios were far too narrow and "underpowered" for the job.