"I think it's harder on her than it is on me," Gloria Steinem told PEOPLE at Thursday night's premiere of the new HBO documentary executive-produced by Maria Shriver, Paycheck to Paycheck: The Life and Times of Katrina Gilbert.
Explained Steinem, "I can say whatever it is that I feel. But because of her art and because she is known for playing characters, by definition not herself – I think it's more difficult for an actor like Jennifer to be understood as a unique human being."
The co-founder of Ms. magazine and spokesperson for the women's movement going back to the 1960s, Steinem, who will turn 80 this month (she'll celebrate by traveling to South Africa and Botswana, she told PEOPLE), was interviewed by Aniston, 45, in California at February's Makers Conference. Its organizers described it as "a dynamic digital platform showcasing thousands of compelling stories – both known and unknown – from trailblazing women of today and tomorrow."
During their exchange at the conference, Aniston pointed out that for women in the public eye, "our value and worth is dependent on our marital status and or if we've procreated."
As raucous laughter erupted in the room, Steinem replied, "Well, I guess we're in deep s––!"
Because Aniston is sometimes criticized for not going the traditional route by being married and having kids, Steinem posited, "What about George Clooney? Nobody brings that up, and he's much more ostentatiously unmarried with no kids – but in a fine way."
She quickly added, "I admire him as an activist in Africa and for doing all kinds of [good] things. I'm just saying that nobody really asks that question of him."
Steinem also gave Aniston high marks for her interviewing abilities at the conference, where 50 powerful women from different fields gathered, including Marlo Thomas, Jane Lynch and Chelsea Handler.
"I thought that she was very good at it," Steinem says. "It just takes a while to understand there is no one way of being an interviewer. Like all of us, I think she has looked at Barbara Walters, you think, or Oprah Winfrey. We each do it differently."
Of Aniston, Steinem further added, "It was her birthday, actually, and it was very kind of her to spend her birthday that way."