Companies of traveling players performed Commedia dell'arte outdoors, a topic that can be explored from many angles—at what venues? to what sized audience? in what legal or illicit circumstances? What interests me most in Watteau's depiction of a troupe is the lighting by torch and moonlight. Remember Snout's question in A Midsummer Night's Dream, III, i: "Doth the moon shine that night we play our play?"
How much could be seen by how many spectators would vary immensely by how full the moon was on a given night, and whether the sky was clear. Torches would illuminate in a small area and add glaring, smoky focal points. But, oh, but what else could be going on off in the darkness—that's for the writer to visualize!