Airline passenger captures two figures appearing to stand on a cloud layer

A video taken by an airline passenger reportedly during a commercial flight over the UK shows what seem to be two figures standing on a layer of clouds. 

The intriguing footage has sparked a wave of speculation online. While some viewers suggest the figures could be supernatural beings, closer analysis of the footage reveals additional shapes emerging through the clouds as the camera pans from left to right, image below.

This has led others to theorize that the "figures" might actually be exhaust stacks or other tall structures releasing steam, breaking through a fog layer and creating an illusion of human-like forms. 

Rather than supernatural entities, the phenomenon is more likely an example of pareidolia, a psychological tendency to perceive familiar shapes, such as faces or figures, in random patterns.