Up for Grabs and Needs a Better Description. I've seen this in several works (but can only think of one off-hand). A female character- this is a pretty much Always Female trope- undresses/changes behind a screen, and Sexy Silhouette will be in play as well as the possibility of the person talking to them seeing some skin- this has some overlap with Scenery Censor). Often, this trope is used with respect to actresses toward visiting "gentlemen callers" (the example which brought this to mind is an instance of this in the first episode of Mr Selfridge).
Hello, Unknown Troper. You'll need to get known to lend a hand here.