This Rare Optical Sight Called 'Brocken Spectre' Occurs When Your Shadow Is Cast Upon A Cloud Opposite A strong Light Source

The phenomenon is also known as a “mountain spectre” because it most commonly occurs when an observer stands at a higher altitude on a mountain and sees their shadow cast on a cloud at a lower altitude. A Brocken spectre, on the other hand, can occur in any setting when an observer’s magnified (and seemingly enormous) shadow is cast in mid air against any type of cloud opposite a strong light source.

To include a glory, the clouds or fog causing the phenomenon must be located below the observer, in a straight line with the Sun's/position Moon's in the sky and the observer's eye. As a result, the glory is frequently seen from a high vantage point, such as a mountain, tall building, or flying aircraft, as shown above. In the latter case, the glory always surrounds the plane if it is flying low enough for its shadow to be visible on the clouds. This phenomenon is known as 'The Glory of the Pilot'.