From what I can see here, this looks like a temporary thing, that never got completed.
My guess would be that the cable leaving the ground in that conduit, was mean't to supply that sign.
But, as Electricman2 said, that wiring has been there a while.
I've never seen a box as rusty as that one holding the timer before, I thought it was tree bark when I first looked at it.
Is that double-adapter on the end of that extension cord weather-proof?.
Also, has that grey piece of Romex in the second pic, been stripped back, bfore it enters the timber post?.
And where that black (flex-looking)wire enters the black steel pipe, in the same pic, is there a bushing on that?.
Rough as guts, eh!.