I mentioned that the next release will have previews of crystal structures … but also molecules.
The molecule fragment images are generated using RDKit as standard line drawings. A few cases like the fullerenes do not work well as 2D depictions, so they are ball-and-stick screenshots.
Phenanthroline
alpha-D-fructofuranose
\ce{C60} fullerene
You can find the whole set here: