Voice and Costumes
It is so obvious when Charlotte is crying that she changes into BD's voice from that of a younger female. And the hairdoo's are obviously from the 60's and ruins the whole backstory.
The prologue in which the 1927 partygoers are dressed in '60s Mystery Date garb is unimaginable and the film's only significant flaw.
It was routine in '60s motion pictures to ignore period detail, but given that BABY JANE (produced by the same team) got their 1917 prologue outfits correct, it seems an inexplicable error that CHARLOTTE would not.
Only Joe Biroc's trademark B&W cinematography helps the viewer if not overlook the mistake then at least forgive it a bit.
But, yeah, one can't conceive of how Mr Aldrich allowed that to get by. In fact, it may be the single greatest living mystery of the movie.
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