Instead of looking at the significance of just the green airdancer, let's look at the entire scene with the airdancer. We get a very lively microcosm of LA: the morning mist at dawn, sprinklers watering a golf course, people exercising at a park, a bright ferris wheel with neon lights, and airdancers making chaotic movements. What all these scenes have in common is life. Even the music is uplifting during this scene. All this life is meant to contrast and really emphasize how dark and loathsome Louis's life is. This is similar to the literary device known as foil, except we are not contrasting characters, we are contrasting scenes.
The scene preceding the airdancer is that of Louis forcing Nina to have sex with him. The scene following the airdancer is that of Louis and his partner missing the big plane crash, and soon after, Louis has his episode in the bathroom. The airdancer scene is nothing like these two scenes, and as you mentioned before, the airdancer scene takes place during the day and the two sandwiching scenes take place during the night.
At face value, airdancers are devices that places of business use to get people's attention. They make a lot of movement and are usually of vibrant color. Airdances don't blend into their environment, they stand out. Sometimes they stand out enough so that people will go into the place of business and buy things. So perhaps you could argue that the airdancer is symbolic to Louis, as they both share the quality of trying to sell things and not being "normal".