Has the vibe of an 18th or early 19th century astronomy; before photography the only way to register what they saw was with sketching materials by their side. Peek through the eyepiece, turn to the paper and draw a bit, eyepiece again, draw a bit more, over and over again.
Take away the dark spheres, and this one looks a bit more like observing an eclipse for its’ duration, committing it as best as possible to visual memory, then doing the drawing immediately after, in one go.