The twin-tailed siren on the cup, accused of occult lineage, while her documented genealogy is stranger: a medieval serpent queen, a phantom Norse woodcut, and a dictionary of symbols.
Documented
The woodcut that never was
The founders chose a twin-tailed siren from old marine books in 1971; the official account cites a Norse woodcut that medievalist Carl Pyrdum showed cannot exist, since the Norse were gone centuries before woodcuts on paper. The logo's curves match the twin-tailed siren plate in J.E. Cirlot's Dictionary of Symbols, and the figure descends from Melusine imagery reaching back to the twelfth-century Otranto cathedral mosaic.
Assessment: Documented: the image lineage is traceable and the official story fails chronology. The logo is medieval; the woodcut is not.
Stories
Everyone reads her as a message
Critics read the siren as seduction personified, occult readings claim her as a goddess or alchemical sign, and both treat the cup as a confession. Meanwhile the company cropped her year by year, from bare-breasted figure to a face and a crown.
Assessment: Stories: every camp reads the siren as intent. The redesigns read her as liability.
Interesting claims
The hidden true form
Melusine's bargain was that she could not be seen on Saturdays, when she became a serpent. A brand that built its myth on an unseeable origin chose the one medieval figure whose story is about a concealed true shape.
Assessment: Interesting: the phantom woodcut is the cover story, and the serpent queen underneath is real.
Sources and further reading
Carl Pyrdum, Got Medieval, Aug 2010, 'The Other Starbucks Mermaid Cover-Up'
Howard Schultz, Pour Your Heart Into It, 1997, the Norse woodcut account
J.E. Cirlot, A Dictionary of Symbols, twin-tailed siren plate