I wanted to soooo bad but there is no way to do it currently BUT!! I hope you will be sufficed knowing that the dimple is used as the growbox Clcik the link below to see it.
Btw, you can already get the NeXT-looking clock in the Dock. Just put the Clock.app in the Dock and in Preferences select Digital. I use that now as my clock and removed the time from the menu bar. Too bad that the day and month are in such small text, since I hate magnification.
BUT!! I hope you will be sufficed knowing that the dimple is used as the growbox