Collecting this sort of anecdote is a personal hobby of mine. Lena Dunham's quote is a sturdy expression of totalitarianism, which most of us learned in grade school is a Very Bad Thing. The totalitarian mindset bends all other rules to those of politics; there are no absolute standards, just applause for the Party and contempt for its enemies. Dunham is saying this quite literally: nasty comments based on appearance are to be forbidden against the Party and its loyal allies, but they're fair game against the Enemy.
This impulse is also expressed in the Left's general comfort with the disgusting misogynism and racism of someone like Bill Maher. As long as his targets are enemies of the Party, like Sarah Palin or Herman Cain, it's all good. If he leveled comparable comments at, say, Michelle Obama, his career would be instantly destroyed.
It makes people squirm to hear this described as "totalitarianism." Good. It should make them uncomfortable. It's more than just shameless hypocrisy. This mindset is dangerous, the soft form of something that can turn brutal with surprising speed. I remain surprised that people of the 21st Century are so willing to dabble in the soft forms and primordial stages of the 20th Century's grim horrors. We should know better.
This barbarism is also unworthy of Americans, whose dignity and common courtesy should not be subject to political imperatives. But as politics infiltrates every moment of our lives - we can't even get through the Oscars without a representative of the regime making an appearance! - the totalitarian impulse becomes more pronounced, not least because the Party is very jealous of its carefully cultivated identity groups, and reacts very badly to members of those groups who present a strong challenge to Party orthodoxy. A few demonstrations of "bad attitude" toward such heretics helps to keep everyone else in line.