Lens is the glass formed to focus light. Lense has become accepted as an modern, alternative spelling. The latter is a verb used to mean “to filter or thin-out”.
The featured image is of the Telectroscope, a fictional device that allows one to see things across a great distance. In this case, this is of a real-life one that supposedly travels from New York City, through the Earth, to London and to allow parties on both sides to see each other in real-time. In reality, they are connected via digital network (Internet). It was installed in 2008.
Here’s a picture of a recently declassified American, Cold War-era spy-satellite. It is, in fact, the size of a school bus: