Mensch told GQ magazine that it was sexist to "trivialise a woman politician based on her appearance".
The backbencher said that her political statements end up "obscured" by talk of how she looks or what she is wearing.
Meanwhile, the author - who took part in the Commons culture, media and sport select committee's questioning of James and Rupert Murdoch last summer - is pictured wearing a £485, leather-fronted, Dolce & Gabbana skirt, paired with a £271 silk blouse by L'Agence.
Mensch went on to admit that she finds it "kind of annoying" that she has not yet been made a parliamentary private secretary by Prime Minister David Cameron.
"It's kind of annoying," she complained. "What do I have to do to get promoted over here? Am I being disloyal? I don't know. I need to sit down with my whip and say, 'What do I have to do?' Every time there is a raft of PPS promotions and my name is not on them, I have to sit down and think, 'What am I doing wrong?'"
"And, on the issue of the photos, thanks all for kind words but that is a make-up artist and genius photog Simon Emmett's way with light."
The 40-year-old quipped: "I don't actually look anything like that in reality."
The full interview appears in the new issue of GQ magazine, out Thursday, January 5.
Watch a behind-the-scenes video of Louise Mensch's GQ photoshoot below: