Sort of a follow-up to Is it legal to preferentially hire men instead of women because women can get pregnant?
The idea is, women tend to be less comfortable with men seeing them naked than men are with women seeing them naked. Therefore, if I'm operating a hospital/clinic where nudity might be necessary, it's preferable for my patients' comfort to hire female nurses & doctors. Concretely, if I need an electrocardiogram performed, if I have female nurses then all my patients will be relatively comfortable; but if I have male nurses then my male patients will be fine but my female patients will not be so comfortable.
The answer in the linked question says it's legal if:
(2) (a) the duties of the position can be performed only by a person having particular physical attributes (other than attributes of strength or stamina) that are not possessed by persons of a different sex from the relevant sex;
However this sounds ambiguous to me: both men and women can perform electrocardiograms, but only women can do it such that female patients are comfortable.