i would like to stop for a moment to propose a new word:
1 Pharmacology (of a molecule) having a structural resemblance to its biological target on a macroscopic level: Prostaglandin E1 looks like an erect penis.
the crucial point in the above example is that Prostaglandin E1 looks like an erect penis* AND is used to treat erectile dysfunction. etymologically, pharma is from the latin pharmaceuticus "of drugs" & cognateis from cognatus "of common descent." i could probably think of a better word to suit this definition. not that it really matters because pharmacognate is almost never needed and is ultimately a useless example of pareidolia** furthermore when you consider many molecules are structurally flexible with rotating bonds it becomes an even more useless term (not that a molecular diagram is in any way an accurate representation of the "actual" molecule in the first place).
nonetheless, certain molecular diagrams do resemble various things, related or unrelated to their behavior. heroin looks like a horseshoe crab, imipramine looks like a kite, MDAI looks like something btw a larva and a bow-tie. they may be shapes in the clouds, man, but that does not mean their shouldn't be a poorly chosen word to describe (a minority of) them!
*with a hydroxylated urethra
** or is it?