W140 95S420 wiper question

[sixto]

Is the US driver side wiper supposed to extend and retract like a 190E or 300E wiper? There's a significant area in the upper left of the windshield that the wiper doesn't clear. The base of the wiper looks like it might house a cam mechanism.

Thanks,
Sixto
95 S420
91 300SE
87 300SDL
83 300SD

ps. It seems to me that the wipers swing the wrong way.