What captivates me about the drawings is the range in detail and accuracy. Keep in mind that naked-eye observations are difficult, limited to the colour sensitivities of the human eye, and often are working at or near the limits of perception --- the fanciful details on Mars are extrapolation of a very small blurry rusty dot.

The detail of the sunspot images is exquisite.

The other aspect is that until the advent of photography, all image preservation was mediated by the human eye, mind, and artistic ability, and often the 2nd or further-removed hand accounts and relating of original events or objects. (See Albrecht Durer's rinocerous for one of my favourite examples of this.) The century or so from the mid-19th through mid-20th century where direct analogue impressions of images, sound, and movement were possible gave us a period of robustly reliable records (within the limits of equipment, and still subject to manipulation). The age of computer-modified and -generated imagery once again leaves us with high-fidelity images which may have remote, little, or no bearing on any actual reality. This includes, for what it's worth, many of the NASA images provided, which are more data interpretations than realistic representations of astronomical objects.