Decades after her tragic death Princess Diana remains a fashion icon, known for her signature shaggy ‘do that inspired “hordes of women” to copy the short haircut. It shouldn’t be surprising that in her brother Charles Spencer’s book Swan Song: Diana, My Sister that he would dive into how fashion impacted her life as a royal. So naturally more tea about Princess Diana has rolled around after the book’s release, and this time it’s about her hair.…