Some of my favorite illustrations to look closely at, are cross-section pieces. To see how an artist has envisioned the inner workings of any given being or mech is really fun. I had an acquaintance in high school that would do very intrigue cross-sections of anime robots. It was really enjoyable watching the process in person. To this day, I do not have the patience to work out the intricacies of mechanisms nor to draft them.
A favorite aesthetic.