Modesty in general is an intreresting topic, and I'm not sure I have many firm ideas to offer. Recently, I've become aware of cheerleading as an actual sport (rather than the "sideline" cheerleaders that you see supporting games). I got to thinking one day about how we usually have women cover their breasts when in public, but somehow bare midriffs are completely OK. Interesting, that, since the abs are usually what turn me on most (and potentially off, as well, if there's too much fat showing). I'm not primarily a breast man.
Not that I'm complaining, because that means more great pics on the web. But if I were a parent, my daughter would be forbidden from showing any of that until she was 18.
I'm definitely a clothing fetishist, as many who read my posts (if any do), can gather. Masks (surgical masks, half mask cartridge respirators, cloth covid-19 masks, anesthesia masks), but also cheer uniforms as mentioned, school outfits (knee-length skirt, with opaque tights), soccer kits (especially socks and cleats together), and sleepwear (footed pajamas and frilly nightgowns).
Masks, to me, can make a girl seem submissive. Not sure about modest, or if that's kind of the same thing. I kind of don't think so, in my personal context, which requires a female patient to wear a mask to protect her immune system or lungs. Not to look more acceptable (though I would think she looks stunning with the right mask on, and the right fit).
Frilly nightgowns are meant to be cute, not sexy, but cute is sexy to me at times. And they do look modest. They cover a lot. Especially, as in the Nutcracker, Clara's case, where she also often wears opaque stockings.
As I write this, I go back to the OP, where @kenneth177 asks what modesty is "about". I think it's just imbued in most of us by our parents, who want to protect us, at least until we can protect ourselves. And the goes especially for the daughters, and the reasons are rooted in millenia past.