This is from the Drone Survival Guide, a to-scale silhouette mock-up of the world's drones by Ruben Pater.

Pater believes that as drones become increasingly common, people should have the tools to identify them at a moment's notice. The ability to recognize a drone by their silhouette, Pater thinks, is much like our ancestors' ability to spot predators from afar.

In-depth information for how best to prepare for the coming reality of a drone-filled world by can be found at Pater's website. Reflective copies of the guide — useful for possibly being able to disrupt a drone's sensor, though Pater admits he's not entirely sure — can be purchased in multiple languages.