Honestly, does Lois really have a popular house-style character design? With MJ most artists reference the Romita look (dimples, bangs, red hair) which I think is pretty recognizable to a comic book audience. If not that, they go for the J Scott Campbell design. And I think the recognizability helps with something like a variant cover. I can't think of one universal defining look for Lois (other than brunette in business attire in a Superman comic.) She's had so many different styles and looks over the years. But MJ is still rocking her 60s 'do.