I don't think this statement is true (I've personally heard men say bloody awful things), but many women certainly do seem to police each others' appearance and behaviour - weight gain, weight loss, skirt too short, drinks too much - in such a way that men like to notice and point it out.
To me, this is symptomatic of an oppressed group. Low-level employees in a work environment, for example, will often focus on each other; how are they getting ahead? Are they making us all look bad? Why are they getting special treatment? Oh good, they've done that wrong too so I don't feel such a failure. Should I be different somehow?
And on. When the boss is out of earshot in a social environment, he/she will be the butt of jokes, slagged off and complained about. Some real and important issues will often arise, and there will be a sense of bonding between the employees with the boss absent.
When women relax and bond with each other in this way, complaints/jokes about male partners will regularly come into conversation, and there is usually much in common: He doesn't listen, he doesn't do enough, he doesn't empathise with me etc.
A lot of women don't realise that whilst in a way they are complaining about their individual partners, they are actually recognizing a pattern of behaviour in men that is inevitable in patriarchal society, where things are skewed in favour of men (although how much this benefits men is questionable) and so they feel disinclined to alter their behaviour & appearance. Therefore, women must change themselves if they feel something is wrong.
Best not question the 'boss', ie male-dominated society.
There are patterns of behaviour in women under patriarchy too, like policing each others' behaviour and appearance.
Round and round we go.
Thus, nothing short of a revolution is going to get rid of Heat magazine.