The car was conceived as a "lady's car" for around-shopping and that door was to give her easy access for putting her shopping bags in without having to bend down or do anything which might break her finger-nails..
Hence the very feminine name, but I think the concept would be given pretty short-shrift by most of today's ladies..!
It was of course based on a Fiat 850 Coupé and was designed by Il Maestro Giugiaro. It was first shown alongside his slightly different Maserati Ghibli in 1966; guess which one of them Giorgetto has in his collection today!