When Roseanne removes her bed sheets in the doorway she doesn't quite stay out of sight and we can see she's not nude but wearing a beige wrap.
Harriet Winkler wears and open back dress and her bare back is visible as she moves inside with Mr. Roarke and Tattoo. Moments later when she is invisible and disrobes she removes a normal bra which would have been visible if she had been wearing it with her open back dress.
When the invisible woman falls into the hot springs you don't see a hollow space in the water she would still be displacing by her body.
The string holding up the lipstick held by the invisible woman is visible.
When the "invisible" Harriet Winkler smacks the Dynamite Girl with the cane, the line suspending the cane can clearly be seen.