Possibly some might (reasonably!) think "casual" means more revealing, for example, instead of simply 'less formal' (that one might dress less formally than one would usually for a funeral).
Of course, that kind of "casual" that means modern American showing a lot of extra skin would stop being "modest". Definitely not an ok 'casual' (see just below). But the only other danger beside showing too much skin is dressing too richly:
8 Therefore I want the men everywhere to pray, lifting up holy hands without anger or disputing.
9 I also want the women to dress modestly, with decency and propriety, adorning themselves, not with elaborate hairstyles or gold or pearls or expensive clothes,
10 but with good deeds, appropriate for women who profess to worship God."
I don't think most of us would ever make the mistake of dressing too richly, as if to make ourselves better-than-others by clothing, as if higher in status by clothing.
We do need 'good' 'clothes' of a kind: "...good deeds...", and that's for both genders of course.
So, that pretty much exhausts the details about physical clothing as I think of them, this passage just above. It's the other kind: the spiritual clothing, that really does matter, we learn.