Rare Black Triangle TR3B cruising at low altitude over London, UK

It doesn't exist officially, but reports generally describe black triangle TR3B crafts as large, silent, black triangular objects hovering or slowly cruising at low altitudes over cities and highways. Sightings usually take place at night. These objects are often described as having pulsing colored lights that appear at each corner of the triangle.


Now, on the evening of May 23, 2020 Louis-Julian saw a strange large triangle craft which was certainly not a plane, helicopter or drone hovering at low altitude over London, UK, on which Louis-Julian decided to record the craft which has all the features of the black triangle TR3B.

What would have been the reason to fly this anti-gravity craft at such a low altitude over London.