That design is actually a solar still, a concept taught in survival training. You can put salt water or urine in the contained cup, and the condensate that drips down the sides of the cover will be distilled water. I would guess that the drawback for tobacco is that you would need to set up a separate still for each individual plant, and laboriously replenish the water in the inner cup on a regular basis. So that would limit its application to a manageably small grow.
Bob