How can you tell?
Those images in the air are generally man-made, I have found. Having to do with several technologies, HAARP and “Project Bluebeam” or Directed Energy Weapons (DEW) among them.
Have seen some just appear to be made by invisible drones- sometimes called sylphs. Believe these to be simply demonic, as they can generally be dissipated by prayer, particularly the “Binding and Loosing” of Matthew 16:19, 18:18, while claiming Luke 10:19.