It isn’t easy to coax a smile out of January Jones. Perched on a velveteen banquette at the NoMad hotel in the Flatiron district recently, Ms. Jones didn’t engage in the dithery banter that in Hollywood passes for charm.

What she offered instead was a credible impersonation of Betty Draper Francis, the sweet and sullen character she plays in “Mad Men,” the role that has turned her into an emblem of glamour as wintry as her name.

She was dressed down in a T-shirt, hoodie and fashionably shredded MiH jeans. But easygoing as she appeared, you could be forgiven for confusing Ms. Jones with her starchy alter ego, the immaculate Hitchcock blonde married early in the series to the philandering Don Draper, then to Henry Francis, the small-town politician who rescues her from a life of lies.

Certainly, viewers seem perplexed. They conflate the actress with her role, argues Natasha Vargas-Cooper, a pop-culture historian and the author of “Mad Men Unbuttoned: A Romp Through 1960s America” — maybe because of the intimacy of TV. “She is in our living rooms,” Ms. Vargas-Cooper said in a telephone interview, “and that just brings up a lot of unsettling feelings.”