Wow! You are right http://www.android.com/versions/kit-kat-4-4/

Holy crap: http://www.android.com/new/images/banners/meet1-1200.jpg

That only appears to go back a couple versions. For example, times in ICS screenshots are all over the place: http://www.android.com/versions/ice-cream-sandwich-4-0/

it seems to be valid for the official press photos of the nexus device corresponding to the android version, at least as far back as the Nexus S at 2:30.

One clock on that page says 4:30. I wader if they reused an image from an earlier version?

How better to version the screenshots? Clever.

IMHO, this is indeed a much more of a real and clever usage of the clock in screenshots. But since its not related to the brainchild of Apple or Steve Jobs, your observation is most likely to languish in the comments section of this article rather than the front page of Hacker news.