Art growing more “realistic” and photo-referenced is probably the source of the recent lack of mask-emoting. The mask was static in Moon Knight, in Fraction/Larrocca’s Iron Man and usually, but not always, in Bendis’ Avengers books. The good Whitney stories really predate all that art shift by a good couple of decades, though.
As a general rule, pretty much any story where she’s a driving character has her emote a lot. Bendis tends to feature her more as a plot device than a character, but when she gets a sequence where her emotions matter, like the Bachalo-drawn bit when she and the Hood hook up, the mask emotes. Bachalo especially gives her this ridiculously adorable pout. (I always use Bachalo’s MM for my icons. She’s just…SO cute.)
Madame Masque showed up….proooooooobably around the same general timeframe that Gene Colan started drawing Iron Man’s mask emoting? So having the mask emote wasn’t something they would necessary shy away from in the beginning and it was very necessary once she was a major love interest for Tony. It is something that is steadily falling out of favor, though, which is a shame because she’s a character that wears her heart on her sleeve, for good or for ill.
Usually ill, but that’s supervillainy for you.