Bosh. Taking your pants off isn’t “redefining” anything. It’s plain old stripping, even in black and white.
First ladies should be “classy” first .... if they can manage to be sexy while being classy, then more power to ‘em. No pants is not ‘classy’.
I *think* the one who might appear pantless is the teen daughter, and she’s more than likely wearing short shorts under the jacket. Suggestive, at the very least, but I’d be surprised if she were really pantless.
Sexiness in a First Lady isn’t something we have to worry about any too soon in the U.S.A.