I think that there are probably a number of things that make the clear plastic bottle on the dark surface uniquely useful for this.

1) clear to UV - rules out opaque bottles and glass bottles which are opaque to UV

2) Heat concentration - rules out metal containers

3) insulative properties of plastic - rules out metal containers

4) sealed from recontamination - rules out open puddles

5) food-grade plastic won't introduce chemical contaminants. - rules out black-top

6) Time. This process takes 1/2 day or so because it doesn't really get that hot.

If you set up a double layer window on a very shallow slant, paint the underside black, let water flow very slowly between the panes, you will get considerable condensation on the upper pane which will flow down to the bottom for collection. The condensate is distilled and drinkable. If you separate the panes enough you can rig a trough at the bottom of the upper pane to catch and divert the condensate. If you further make a highly convoluted path for the water to flow down the lower pane by dribbling silicone caulking or some similar clear substance on the glass you can get the flowing water to move accross the surface extremely slowly thereby increasing the heating and subsequent condensation. Don't allow any air to flow between the panes of glass. This simple still is equivalent to those used in solar desalination plants. Eventually you will need to open it up and clean residue from the bottom pane.