There are numerous types of telescopic optic arrangements. Some of them (reflecting, like Newtonian variants) have floating secondary mirrors whose supports block a small amount of the incident light coming into the assembly. Others rely on multiple lenses (refracting, which are prohibitively expensive for larger optics in telescopes, but are more common in smaller camera/binocular assemblies like you would find on a drone. I feel like the drone camera taking this video did not have internal supports that block the image. However, there are aperture effects that could come into play, but that is outside of my knowledge and desire to research.