Some amount of ink on some paper ? !

You are somehow getting close to the concept here but No. No paper and no ink.

is it coffee on the kitchen bench?

Looks like an oil stain. I had cars that did that.

Car engine oil on ground !
Arthur said it first of course ! so if it is right Arthur is winner ;)

mo

No. Not in kitchen and no coffee. But very good guess and I think coffee on a granite counter top would appear exactly the same as this.

Very close and you are in totally right direction but absolutely nothing to do with oil stain.
Clue: You are right to see this on the street and over the asphalt!

Not yet Mo and see the above clues. We seems to be close to the end.
Lets see if this can be solve soon.
I thought this is going to last longer...

is it just a water puddle on the hard surface

Hard surface: Yes (Its asphalt).
Water: No.
Clue: All the black area marking is not made up of any material!!! In fact no different from remaining brighter area.

Could it just be a shadow on the asphalt?

Bravo and "Shadow" is correct but shadow or what?
If I don't get the correct answer in 24 hours, your are the winner but lets wait a beat more and try to say what it is or what is this subject, casting this shadow.
Clue: Has to do with photography!